They all look like:
And the story for hl2 is fuckin amazing yo. You gotta play single player with that. Day Of Defeat is AOK, and Deathmatch is horrible IMHO.
I haven't actually played any of the games, but I've watched my brothers play. I do play garry's mod, which is fuckin awesome.
I'm thinking of starting an HL2 mod. Apparently they're not too hard to make and I got an epic idea.