To add a couple things to what Kali was saying...
First, I posted a whole bunch of impressions on E3 trailers and the Lost Planet demo in <a href="
viewtopic.php?t=10450">this thread</a>.
Also, games that I think look pretty cool/deserve tracking as they get closer to release:
-Lost Planet
-Bioshock
-Viva Pinata
-Mass Effect
-Phantasy Star Universe
-Too Human
-Huxley
-F.E.A.R.
-Gears of War
-Live Arcade Volume 2 (Lumines Live, Contra, Paperboy, Defender, Galaga)
The second wave of 360 games are looking to be pretty safe bets - of course, I'd wait for actual reviews to come out if you're thinking of buying a 360 based on those games alone. The current games aren't half bad, though - I like my 360 a lot, and actually have spent the last two nights just downloading trailers, demos, and trial versions of Arcade titles (as you can see from my gamercard). And this is *before* I've spent any quality time with Oblivion.