It's pretty close and not easily decided, but I'd say XBox.

GameCube was a lot more powerful than it would appear to be, both by looks of the machine and by the numbers on paper, because of it's efficient design. At the end of the day though, XBox's high raw power definitely put it ahead. There were quite a few games there that I didn't see possible on GameCube, but it held it's own more than adequately. And yes, PS2 was "their bitch" technically, both were way above it and the Dreamcast.

An easy win for Xbox. I had both Gamecube and Xbox back then and used a projector (Panasonic AE100) and there was no comparison really. Xbox was amazing for its day. There were a huge number of Xbox games that would never be possible on gamecube thanks to its greater memory and hard drive and nothing the Xbox couldn't do that was on Gamecube. I don't know how good Rogue Squadron would be on Xbox but Factor 5 did some amazing stuff for that game including hand assembly of some code I believe. Technically the xbox gpu was about 20 gflops with a improved feature set over the gamecube's 8 gflops gpu. The cpu integer performance of xbox was about 2,500 mips compared to about 1,200 on gamecube. The Gamecube was limited by small optical discs as well as limited main memory.

Many multiformat games were cut down on Gamecube. I remember playing Medal of Honor Frontline on both consoles and there was a lot of missing graphic detail on gamecube. Same thing happened on many games.

http://www.youtubedoubler.com/?video1=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dn9as4uH4H_M&start1=20&video2=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DSmM_NE4yyr8&start2=200&authorName=snoopsagan

this isn't even a question. anybody saying GameCube is delusional.

it's arguable the wii isn't even more powerful than xbox,. let alone gamecube. doom 3 xbox looks way better than the conduit on wii for example.