If we are talking hardware quality, GC pwns all of this and last gens home consoles.
Hardware quality consists of a number of things IMO;
physical durabilty [GC>XB>>>>PS2]
electronic durability [GC>>>XB>>PS2]
design [GC>PS2>>>XB] (PS2 slim would be above GC though)
hardware capabilities (tech specs) [XB>GC>>>>PS2]
controller (yes it is part of hardware) [GC>>PS2>>>>XBsmall>>>>>>>>>>>XB]
practicality of design [PS2>>GC>>>>>>XB]
by the way i basically made all that up on the spot.
looking at my recently made up list, and taking into account various weighting i am going to apply to stuff (ie controller is more important than the design)
I can easily see GC>>>>>PS2>>XB.
What was wrong with the GC was it set of on the wrong foot and had a poor selection of third partys on board etc
If i apply the same things to this gen I would say
Wii>PS3>>>360 (you can tell i don't put much of a weight onto tech specs)
None of the above however manages to affect the sales much... sales are down to games and marketing for the most part.
