I have a solo character and a co-op character. I can tell you this:chubigans said:So who's mostly playing single player only? Would anyone recommend the game based on SP alone, because that's where the majority of my time would be.
Co-op is incredibly fun. It's faster paced and much more difficult. The loot is always better and overall it's a different experience. Just make sure to play with friends or GAF groups. Most of the GAF groups I've put together have been excellent. A lot of people on the list don't want to play co-op though, which is silly, you guys shouldn't have added yourselves.
Single player is still great. There are some things you just miss out on when playing co-op. You don't really have the time to sit there and compare items, open up all the loot chests and take in the entire game when you've got people waiting on you. You'll miss almost all of the backstory of Pandora. I know I couldn't ever hear the annoying voice of Tannis over the talking co-op players and never had the time to read (only skimmed) the mission logs.
If you're going to play Borderlands alone for the majority of the time you'll still enjoy yourself. It's a great game, regardless of the amount of players involved. 90% of the press reviews you've seen have been based on SP only. Jeff Gerstmann from Giant Bomb only played co-op for the first time when he did the Quick Look iirc.