Don't factor in length. The single player was a totally enthralling experience where you felt like you were in the middle of a serious war and took a large role in it.

However, the multiplayer has many addicting modes and has damn near endless fun.

Which one was (or still is) more fun to you?

I LOVED the single, but I'd still have to say Multi for playing with friends.

I think the SP was extremely fun, but MP gets my vote. It's probably the best online console FPS that I've played.

Tough one... I loved the single player, was short and sweet.. The length didn't phase me at all... It kept me interested.

Multiplayer is fun as all hell though.. So i'd say Multiplayer, as i have played multiplayer for longer than i have played single in total :P

Multiplayer for sure.  I learn something new each week, whether it be a snipe spot, strategy, etc.

I would have to say the single player. I thought the multiplayer was really fun but it got boring to me after a while.

i didnt really like SP but MP was awesome

Both awesome but I'd have to say multi-player

I enjoyed the Single player more, Cod 4 Multi doesn't really do it for me. Too easy to get kills and too much nade spam.

Of course multi :p

I would have to say multiplayer.

Multiplayer, though the Single was an extremely enjoyable experience.

Multiplayer, but I did have a very good time going trough the Singleplayer campaign, was nice to play from both a SAS and USMC perspective, yes it was short if you played it all in one sitting, but I had a fun time going through it so that's all that matters, it's also without a doubt, the best singleplayer ever in a Call of Duty game yet.

Pretty much like everyone else so far, I love the SP, but I'd have to give my vote to the MP. Days of fun online.

Love the single player campaign but multi player is where it's at.

I like both, but multiplayer kept me coming back

this is the first game where it feels like the single player was an afterthought. the multiplayer is the games core and its awesome. mp all the way

Loved Single-player but Multiplayer is where all the fun is.

If it's a story like Metal Gear Solid, i'd vote for that. But the majority of stories aren't as gripping as that, nothing against the other games. They may still be great, but to me they don't measure up to Metal Gear Solid.

I liked the multiplayer better, but the single player is awesome as well!

MP, Sp is good.

Can I say both, I played Single player probably 4-5 times. But mutliplayer had be hooked on the game after I completed single player.