Portal was like a really, REALLY fun rollercoaster.
all over too quickly. But apparently, how quickly (or how slow) you finish Portal depends on your IQ.
As for Episode 2, it was hella good, if albeit more system-demanding then HL2/ep 1. Especially the in-game 'cutscenes' (the lagged me like you wouldnt believe)
TF2 got pretty boring pretty quickly too (like any good multiplayer game, its full of bad idiots)