I myself have always preferred single player. Don't get me wrong, a fun online RTS match is great, and Team Fortress 2 will always be one of the most addicting games ever...online games are good...

But I like single player better. Nothing is better to me then a well-crafted, brilliantly designed single player saga. No multiplayer game can top that.

Sure, multiplayer is more replayable, but to me you can't really compare say, Counter Strike Source, fun, but full of irritating people and relatively shallow with no story, to a superbly made, detailed, story rich game such as BioShock, free for you to experience on your own with no annoying people.

One of my favorite parts of games is how memorable they are, and how creative. For that reason, I prefer Portal to TF2 even though TF2 has given me about 100 hours of gameplay vs. like 7 for Portal...

Anyway, I'm just rambling, so which do you prefer?

Good question.
I find myself enjoying single player games a lot more, but multiplayer games a lot longer, so it all equals out in the end.

It depends on the game, but overall multiplayer is better in my view.

single player hands down, games are like movies or books to me.

I prefer single player to online play even though i play online games most days. I can play a Single player game countless times if its fun.

Single player.

I generally prefer single player but get bored after a play through or few(unless I really like it).

Though I do like the competitive aspects of multiplayer games.

For playing games with other people I prefer board games.

Single player gaming: video games.

Multiplayer for RTS and action base games, singleplayer for RPGs.

Single player without a doubt. The way I see it, single player, if the storyline and gameplay are engaging enough, can create memories for years, random example : "Man, when Psycho Mantis read my PS1 memory card and knew that I loved Symphony Of The Night, I nearly crapped my pants." Multiplayer, if the online is great (or old school split screen), can add to the experience but IMO is not as memorable as single player.