I bought an N64 recently due to the Pokemon Snap video. I was a Playstation kid back in the day, but had friends with N64s. My purchase came with Mario Kart, Goldeneye and San Fran Rush. I am looking for other games that I should play (I own OoT and Majora's Mask for GameCube) but am mainly looking for co-op stuff to play with the girlfriend or when friends are over for a bit of nostalgia. Games can be co-op/ splitscreen against or just turn based. Just looking to game a bit more with the lady, as she has no real interest in modern games besides watching me play from time to time.

Banjo Kazooie, Paper Mario and Super Mario 64 are on the list to buy already. Thanks!

Mario Parties, Perfect Dark, Turok 2 and if you like Pokemans enough then Pokemon Stadium 2 is something you may enjoy.

Smash Bros. on 64 is still my favorite in the series.

I just found WWF No Mercy for 10$. It was one of my most frequent rentals as a child, this game is sweet.

Follow my example!

Army Men: Sarge's Heroes 2.

Super Smash Bros.

If I owned an N64, I'd totally buy Castlevania 64 as well, even knowing how terrible it is, just as a reminder.

Shadowman on the N64 was one of the best games of that generation, and far better than the execrable PS1 version.

Banjo-Tooie is arguably better than the first.

Silicon Valley?

Body Harvest?

The last two are old as hell, and surely much too dated to enjoy at this point, but they were gems at the time.

I actually enjoyed Armorines, even if it's fairly by-the-numbers stuff.

Jet Fucken Force Gemini

Mario Party 1,2,3 all the way for playing with friends.

Cruis'n USA

Wayne Gretzky's 3D Hockey '98

NFL Blitz

Wave Race 64

@Dagbiker said:

Jet Fucken Force Gemini

Christ, how could I have forgotten that. Stone cold classic.

Murdering sapient bears for days!

Perfect Dark

Rush 2: Extreme Racing USA

Blast Corps

Excite Bike 64 is pretty good and has multiplayer stuff (I think you can play soccer). The original Mario Party is a great game too, though it will murder your controllers. Smash Bros. as mentioned. 1080 Snowboarding is pretty amazing too. 
 
Here's a list of other stuff to consider (I just went through the full list on N64 games): 
Bust-A-Move '99 
Cruis'n USA 
Diddy Kong Racing (this game is amazing!) 
F-Zero X 
Ken Griffey Jr.'s Slugfest (AWW YEAH) 
Kirby 64 
Mario Golf 
Mario Tennis (SO DOPE) 
NFL Blitz or Blitz 2000 (I have the former. They're such fun games. I got mine with a box and manual for like $3 from a video rental store that was closing) 
Pilot Wings 64 
Pokemon Stadium or Pokemon Stadium 2 
Rainbow 6 (I actually got this recently at a yard sale for $2. It's pretty good) 
Road Rash 64 (screw what people say, THIS GAME IS AWESOME) 
Starfox 64 
Star Wars: Rogue Squadron (I've played through that game more times than I can count and I've never owned it, I just rented it a ton when the local video store had 2-for-1 game rentals for $2 a week) 
Tony Hawk's Pro Skater or THPS 2 (great multiplayer) 
Wave Race 64 
WWF: No Mercy OR WWF: Wrestlemania 2000 (though WCW vs. NWO Revenge is still amazing too if you can't find the others) 
Yoshi's Story

Diddy Kong Racing. I sorta feel like its better than Mario Kart, though they are both amazing so a comparison is dumb

Turok 2.

Y'all remember that big fat-lady boss battle. I know y'all remember that.

Some of my favorites:

Mario 64

Zelda: Majora's Mask

Star Fox 64

Wave Race 64

Blast Corps

Mario Tennis

Banjo Kazooie

Rogue Squadron

F-Zero X

Cruis'n USA

Pokemon Stadium could be cool but for me a lot of the joy was transfering pokemon from the Game Boy games. If you don't want to mess with that I'm not sure how great it stands up on its own.

@Dagbiker said:

Jet Fucken Force Gemini

Hell! YEAH!

That game effin rocks! Also, I know it sounds dumb but: Mario Party is so fucking stupid adn fun, I love it. Burned my hands as a child (literally) and we still play it today. It's just mayhem, and even without alcohol I think the game is just incredible, if you have the right mindset.

WWF No Mercy is a must.

If you want to see the very beginnings of true, but VERY FLAWED open world: Body Harvest (VERY FLAWED)

And Drew's right about Blast Corps, that game has some legs.

Harvest Moon 64 is still the pinnacle of the series as far as I'm concerned.

If you like Metal Gear solid. If you like Resi 4 then the one game that mashes alot of the two together is.

A fun Multiplayer game. Atleast with my friends.

I had linked to the Giantbomb page...except no one has made a Operation Winback page...not even for the ps2 version.

Killer Instinct 64

Body Harvest

I really like Bomberman 64. Broke out of the grid into open environments with different types of bombs and chill music. multiplayer was fun, too.

Thanks for all the suggestions so far, keep em coming. I do own a lot of my PS1 games still, so stuff like WWF, THPS, Blitz and what not I do already own and am not totally interested in unless I can get em super cheap. There is a local game store near my apartment that has a lot of N64 games, so hopefully if I buy in buik they will give me a deal. I will check there for a few of these titles prior to eBay/Half/Amazon hunting.

@astonish said:

Is Road Rash 64 better or worse than Road Rash 3D (For PS1)? As Road Rash 3D is one of my fondest PS1 memories.

Both of the Banjo games, Conker's Bad Fur Day. Basically anything Rare made.

It has already been mentioned, but I feel like Harvest Moon 64 deserves a second recommendation. One of my favorite games of all time; I can't recommend it enough.

@MikkaQ said:

I just found WWF No Mercy for 10$. It was one of my most frequent rentals as a child, this game is sweet.

Follow my example!

You kinda overpaid.......

But games you should get, I would say Blast Corps, WWF No Mercy, Extreme G, Star Fox 64, and Banjo Kazooie. If you can play Conker somehow I would go for it, but it's really expensive.

San Francisco Rush!

@Dagbiker said:

Jet Fucken Force Gemini

I was planning on making this exact post.

@Elyk247 said:

@MikkaQ said:

I just found WWF No Mercy for 10$. It was one of my most frequent rentals as a child, this game is sweet.

Follow my example!

You kinda overpaid.......

But games you should get, I would say Blast Corps, WWF No Mercy, Extreme G, Star Fox 64, and Banjo Kazooie. If you can play Conker somehow I would go for it, but it's really expensive.

For having it be next door to my house, that was definitely worth every penny.

Conker's Bad Fur Day

Nobody has said Paper Mario yet?!

EDIT: Someone above me has.

@drewbert said:

Blast Corps

This! 1000x this! Blast Corps was the reason I re-bought a 64 and is still one of my all-time favorite games. But this game is single player, so for Co-Op I would say...

-You NEED at least 1 "Mario Party" game, just so you two can compare blisters the next day.

-"NFL Blitz". Extremely easy to learn, and even more fun to play.

-My fiance insist I mention "Star-Wars Podracing".

Ogre Battle 64

@Tag said:

Ogre Battle 64

This. But it may actually be cheaper to just buy a Wii and get it on virtual console.

Mischief Makers. Admittedly this is not Treasure's finest hour, but still its a fun platformer.

Anything by Rare from that era is probably worth playing. You've already got Banjo-Kazooie, so you may as well go ahead and get Banjo-Tooie as well. Conker's BFD is similarly great, though when I played Donkey Kong 64 a few years ago I was kind of bummed that it didn't hold up as well as I expected.

But if you're more focused on multiplayer and such, the first few Mario Party games are alright assuming you're willing to be suitably ironic about the whole thing. Same goes for N64 Smash Bros.

Am I really the first to suggest Donkey Kong 64? Just make sure you have the expansion slot thing.

@mtcantor said:

@Tag said:

Ogre Battle 64

This. But it may actually be cheaper to just buy a Wii and get it on virtual console.

Already own a Wii, looking for an authentic experience however. Hence the purchase.

@FonkyMucker said:

@drewbert said:

Blast Corps

This! 1000x this! Blast Corps was the reason I re-bought a 64 and is still one of my all-time favorite games. But this game is single player, so for Co-Op I would say...

-You NEED at least 1 "Mario Party" game, just so you two can compare blisters the next day.

-"NFL Blitz". Extremely easy to learn, and even more fun to play.

-My fiance insist I mention "Star-Wars Podracing".

I was never a fan of the Podracing game, however Blitz with 4 controllers might be fun. I used to love playing it on my PS1 with friends. The Mario Party games appear to be around $30 each, any of them you recommend the most? I am not looking to go crazy with this system; just want the bare min for a good collection.

Goldeneye.

@Subject2Change said:

I was never a fan of the Podracing game, however Blitz with 4 controllers might be fun. I used to love playing it on my PS1 with friends. The Mario Party games appear to be around $30 each, any of them you recommend the most? I am not looking to go crazy with this system; just want the bare min for a good collection.

Mario Party 2 is what I'd consider the best in the series but even so, 30 bucks is too much for it.

@Subject2Change: I have the first Mario Party for no reason other than it was free....but a Mario Party on the 64 is some of the most co-op fun you will have on the system.

Sucks that you can only find it for $30. Going off on a tangent here, but I find that Amazon has taken the thrill out of going to used game stores. Back in the day you could come across a place that has a slightly rare game and didn't know it or care so they just had it marketed based on what the art looked like. Now every Tom, Dick, and Harry can google a game and see exactly how much to charge you.

Perhaps try craigslist and do a "wanting to buy" post.

I can't help but notice that nobody has mentioned Beetle Adventure Racing. It's okay, not everyone has the same impeccable taste as I.

Ogre Battle 64 & Harvest Moon.

@FonkyMucker said:

@Subject2Change: I have the first Mario Party for no reason other than it was free....but a Mario Party on the 64 is some of the most co-op fun you will have on the system.

Sucks that you can only find it for $30. Going off on a tangent here, but I find that Amazon has taken the thrill out of going to used game stores. Back in the day you could come across a place that has a slightly rare game and didn't know it or care so they just had it marketed based on what the art looked like. Now every Tom, Dick, and Harry can google a game and see exactly how much to charge you.

Perhaps try craigslist and do a "wanting to buy" post.

There is a local game/comic shop by me that has a large selection, but i've never looked through what they have. I hope being it's N64 games they are willing to part with em cheaply to get rid of em. I will check CL tho and see if anyone has a collection or such for sale.

Rogue Squadron. Fucking awesome game.

Mischief Makers

@MikkaQ said:

I just found WWF No Mercy for 10$. It was one of my most frequent rentals as a child, this game is sweet.

Follow my example!

Best N64 game!

@Subject2Change: The multiplayer modes in Conker's Bad Fur Day are RIDICULOUS! I finally forced two of my friends to play that with me a few weeks ago. Nazi teddy bears sort of reenacting the invasion of Normandy or just hacking each other to pieces with katanas while the other one has a rocket launch is hilarious stupid fun.

I also strongly suggest you get Diddy Kong Racing. Awesome kart racing/plane racing/hovercrafting with a full overworld and endbosses.