I already have Half Life 2 which is good, but I've never completed it, I lost interest towards the end of the game. I know it's illegal to not gush all over HL2, but I just found it really dull, and I didn't like where the story was going.
I love Portal, I bought it on its own because I didn't care about Team Fortress 2.
I do have microphone and headphones I could use for multiplayer, but I've only ever been exposed to hostile assholes in online multiplayer, especially as a new player.
I wish there was a demo of Dragon Age, I'm curious about the game but I'm not sure I want to blow £30 when I might not play it.