This month's Chasseurs d'Images includes a systematic test using the DXO tool of all current digital SLR's:

Canon EOS 300D
Canon EOS 10D
Canon EOS 1D Mark 2
Canon EOS 1Ds
Fuji S2
Kodak DSC ProN
Nikon D70
Nikon D100
Nikon D2H
Olympus E-1
Pentax *istD
Sigma SD10

It includes precise measurements of noise at all ISO settings, the effect of in-camera filters, etc. Unfortunately it's all in French and probably not available in your part of the world. It's also much too long to reproduce here, not to mention infringement of copyright.