If you've bought a PC video card in the last year you owe it to yourself to get Far Cry, at least the demo. This is the first game to take real advantage of pixel shaders and insane polygon counts to deliver fantastic graphics.
The gameplay is great too. The AI gives a good challenge, flanking and cooperating to give you a hard time. And the level design is terrific, really taking advantage of the huge render distances. Lots of fun running to a high spot on an island and sniping folks half a kilometre away.
Two glitches to be aware of. The copy protection is user-hostile. And on my GeForce Ti4200 the game crashes regularly unless I underclock the video card 5%. Weird thing is it doesn't seem to be heat related.