Best Router for Xbox 360 Gaming

[VGI-Shinobi]

I'm looking for a cheap ass router that supports 3 different bands A/B/G. I already have a Linksys G router at home but it doesn't work too nicely with the Xbox 360 wireless connection. The reason might be because I tried to watch movies on my Xbox 360 down the basement while its data streaming from the Media Center PC upstairs. Performance will be significant better if I let Xbox 360 utilize the A bandwidth by itself, while all other traffics can continue moving along G.

Thanks for any help.