TriggerHappyAngel said:
Timesplitters: Future Perfect, which is also the best multiplayer shooter imo.
This.
Short but awesome campaign with lots of variation.
Tons of humor and still managing to have a decent story.
Arcade and Challenge modes to expand the single player experience (from zombie beheading to monkey electrocution).
Multiplayer consisting of co-op, 1-4 player split-screen and an online multiplayer.
About 150 playable characters.
A map maker.
The option to make your own missions in that map maker.
About 13 different multiplayer modes.
40+ weapons ranging from old western revolvers to futuristic pulse shotguns (and guns with secondary fire, damn, I love secondary fire).
Very decent soundtrack courtesy of Graeme Norgate.
Interesting graphical style that made everything ever so slightly cartoonish and gave characters in the cut-scenes very rich expressions.
There's not a single shooter out there that can mimic this awesomeness.