I preordered Killzone 3....and now I don't want it for some reason. I played the single player demo of killzone 3 and it was BORING. The multiplayer was fantastic however. Bulletstorm seems to have good single player......or am i wrong? Is there multiplayer?

Do what I did, get both. 
There is a horde mode multiplayer in bulletstorm

Renting both.

Getting Killzone 3.  Multiplayer beta was fantastic, could care less about the singleplayer.

I'll lend my voice to the Killzone crowd. It might be a bit more conventional, but it's pretty well crafted.

Both great games. Since I already have one I'd go with Killzone 3.

I thought the Killzone 3 campaign was a blast but the multiplayer is where it really shines. 
 
I'd go with Killzone, I'm waiting for a price drop on bulletstorm.

That and Bulletstorm being a mainly single-player affair, the 5-hour campaign just isn't gonna cut it. And Kz3 multiplayer looks awesome.

Killzone 3.

If you can only afford one I can only assume that you want some value.
After 30min of bulletstorm  the hole kill with skill (kicking stuff, the slowmo and whip) you have pretty much seen it.
The singplayer is fun and I want to finish it but I cant see me spending hour after hour in coop horde mode.
Dont own a ps3 but Killzone 3 multiplayer seems freaking awsome and will give you alot more hours.

Based on what I've read.  If you want competitive multiplayer, get Killzone; if you want more unique gameplay but you don't need competitive multi, get Bulletstorm

Bulletzone: 3rd Storm.

Killzone 3 will last a lot longer than a 6 hour campaign and co-op.

The multiplayer will last longer in Killzone 3 and make it a better purchase. Apparently Bulletstorm is really really short.

I got both. RIFT as well. Busy week.

I bought Killzone 3 since I beat 2 and liked it, and I dunno 3 just didn't grab me as well as 2 did.  The menu's seem bland, and it just doesn't feel as exciting.   I picked up Bulletstorm today since it looks just like a whole different feel.  Something crazy and fun,  I'm in the mood for something that isn't stressful.

I personally would get Bulletstorm. To me, it stands out more than Killzone does. I'd rather play a crazy-ass shooter than another deadly serious one.

get Black Ops.  Bulletstorm campaign is intellectually insulting, Killzone one promotes Nazis and descrimination instead Black Ops provides a deep psycological triller and quality war hearth-breaking drama

seriusly speaking Killzone 3 multiplayer is very well crafted

Bulletstorm by far. Ive only played Killzone 2, but opinions are that it is pretty much more of the same.

Bulletstorm is some of the most fun I have bad while playing a video game.

@Fearsome121: Actually there's a thread in this forum backing up what IGN said about it being 6 hours. Six hours for a single player game seems to me... shoddy. Also, I'm sorry but I don't see the fascination everyone has with Bulletstorm, it looks like a one trick pony to me and I can't imagine it providing entertainment for any longer than the demo lasted. Maybe it's a good thing it is short then.

@SuperSambo:   It is a 131 trick pony "
 
While not a bad game at all, Bulletstorm it´s like a Subway restaurant.. technically they have a lot of subs fo you to pick, but after a while (not long) they kinda taste all the same, much like skillshots. 

I played only the demos of both but I liked Bulletstorm better. But not by much.

If you can only get one, get Bulletstorm.  I am pretty sure Rico is dead in that timeline.

" I say keep KZ 3, the online part will keep you coming back. Bullitstorm is short, so you will see a bunch at Gamestop soon enough

Killzone; Great multiplayer. The general Victor Sarrano character however put's the Bulletstorm single player over the top. He's one of the funniest villain's in video game history.

If you're not interested in competitive multiplayer, I absolutely think Bulletstorm is the better buy.  Better story (surprisingly), better action, and some funny dialogue from time to time.  The Echoes mode also gives the single player some limited legs after you've finished the campaign.  And it has co-operative "Horde" mode, if you're interested in that. 
 
And I say that as someone who has finished both games.  The Killzone 3 story just never made an impression on me. 
 
- Scott