Well get the vice off your wallet and get a console that you can play COD4 on, if your broke and can't shell out 300 plus the 50 for a game may I suggest the "Orange Box", 6 games for the price of one and I'm sure it will work on your system.
The next console I plan on getting will be the Wii, regardless of it's limitations. If CoD4 isn't available for it, meh.... I despise FPS's on consoles (with exception to the Metroids on the GameCube)
I'm still getting my FPS fixes with UT2004, Red Orchestra and er.... SWAT4 on a rare occasion.
Oh yeah, and original Day of Defeat. I've played Half-Life 2, but I didn't care for it as I did HL1. Too short and they seemed to have focused on the graphics more so then overall gameplay and puzzles. Too short, too simple and not worth the number of years they delayed it imo.