It does everything you expect and more, except a good story.
Multiplayer of course is it's strongest point, playing online with friends or Co-Op is the way this game was truly designed.
The graphics aren't very impressive on the 360 and are MUCH better for a PC that can support better graphics, however they look fine enough and the game will play as you want it.
It does many things right so but there are a few weaknesses it carries.
One is the story, almost non-existent, very confusing and very VERY disappointing overall, as long as you don't care about story you'll be fine though.
Co-op is insanely fun, but on a smaller TV it will be a pain, on a 27in it was very difficult to navigate menus, the UI is very badly designed especially for Co-op but it's not broken just glitchy at times and very clunky. It works however and that's what matters.
The game is very repetitive but has great variety in ways to kill enemies and enemies, although most enemies will fall in one of about 5 different classifications there are many varieties of those enemies.
The guns, there are a ton, you won't be to remember all the guns.
The GOTY is strongly recommended at this point cuz some of the DLC like the bank is almost required IMO to have the most enjoyable experience, not only does the Bank allow you to store new items, it opens new shops which hold much better items than other stores usually do.
The 4 different characters are very unique and different I've only played two of them (Mordecai and Lilith) and must say there's quite a good balance to them from what I've seen. Mordecai gets exposed pretty easily in ambushes and in close up situations cuz he has to rely on shotguns, while a character can Lilith exceeds in Melee and can go invisible and heal. However she suffers from long distance and enemies unlike Mordecai.
The missions are fun, and the aspects and depth to this game is very well done, the game is on the easy side because it's easy to grind or find good guns. And honestly the losses from dying aren't too bad, I actually enjoy this difficulty because it allows you to just play and not worry about big consequences. Losing money is still bad, but it's nowhere near as bad as losing your guns or something.
The game was very well done and created by developers who were gamers themselves, they understood what gamers wanted and tried to create that game for them, and they succeeded.