The Orange Box. Supposedly consisting of the best games in history. WRONG.
Half-Life 2 with episodes. This game is downright boring. You walk for 3 or 4 minutes, fight 2 bad guys that just stand there and shoot, occasionally throwing in the old, walk towards him slowly move, then walk for another 3 or 4 minutes etc. But just when you think the game is getting boring! A great boat mission! Where instead of walking for 3 or 4 minutes, you drive a boat! Then you fight a big flying ship thingy, and kill it by driving back and forth and just shooting it. There is nothing in this game that makes it exciting. Oh look zombie guys (or whatever the hell they are)! Oh wait, they just walk. The gravity gun is the only semi-cool thing here, but it's not even really that good. And the health system feels very dated right now, as I do not enjoy going into a boss battle with 3 health and no shields.
Team Fortress 2. Not bad, just not all that great. Not a lot of players, but it'll do. The game has 1 major flaw. Each map only has one gametype. It's kind of a fun to play, but there are definitely betters out there. The game has a cool art style though. It looks like one of those Saturday morning cartoons. Okay game.
Portal. The best of the bunch. This game won't boggle your mind so much that your head explodes, but it will puzzle you a fair bit. It's pretty funny in places, especially all the, "the cake is a lie" signs. And GLaDOS. She's funny. The portal gun creates interesting ideas, and is fun to muck around with, although, the game is very short, 5 or so hours.
Plus
Portal
TF2 can be fun sometimes
Minus
HL2
HL2 ep1
HL2 ep2
Health system could be better (like FEAR's)