Well I just finished HL-2.
I have to say it was well worth the money! The game just got better as it went on.
The last two levels are just amazing and they're the most fun levels I have ever played in a game. I am not going to say what/how the *weapon* is so much fun.. for those that aren't there yet. But it is just amazing.
I would say if you haven't tried this game yet, it is well worth it.
Bring on the expansions !!!