Recommend a router?

Hi, I'm going to return the D-Link DI-624M... I need a good, EASY TO SET UP router that will get through some walls and give a good signal over a semi-long distance (through 3 rooms with thick walls). Not much more as long as it'll work for an Xbox 360...

The Linksys WRT54G is an easy router. So is the Netgear DG834GT, for those outside North America.

Since you want it easy, it doesn't matter if you get the non-hackable version of the Linksys WRT54G. Just make some easy-to-build antenna pointers to push the signal through the walls:

Parabolic Reflector for Linksys Wireless Routers

As for your other challenge, many people have had problems with their routers and XBoxes. There may be no router that's simple for all purposes. This website might help:

Xbox360 Port Forwarding -=DigiTaL=-