Howdy folks,
You CAN tell if you've got an improved 360 by looking at the box. In fine print it does list the motherboard code word: Zepher is improved and Falcon is the 65nm chips. Either one is good.
Details: http://www.xbox-scene.com/xbox1data/sep/EElyZEZFFAYCVzSDpq.php
As to games, I'm not sure how anyone can look at the current titles available for the PS3 and 360 and rationally conclude that the PS3 has a better list. Maybe someday, but not today.