............

I've only played Half Life 2, but I'd definitly reccomend it... provided you have a good PC, the graphics are freeking amazing... not to mention the physics in it are purely amazing... I think I spent a good 30mins in amazement putting bottles in a crate and shake it around and watching them collide and fall out etc lol

You can't go wrong with half Life 2 - best PC game ever

although... Battlefield 2 rocks too apparently
depends if you want squad based or not

i think half life 2 becauseits more advanced and exciting

You could always check out Americas Army first for FREE!

And it rocks :headbang:

I have half life 2 and it was slightly dissapointing.

However it has one major plus point....

Counter-Strike.

I've played CounterStrike much more that the single player game, which i thought was pretty crap.

As for Battlefield 2, i've played the demo and i'm gonna buy the game soon.

Try the demos of them both.

Battlefield 2

http://www.eagames.com/official/battlefield/battlefield2/us/downloads.jsp

Halflife 2

http://www.half-life2.com/