pixiq is a site with news and technical reviews about digital images. Comparison resports between cameras of similar specification and by different manufactures are a good source for purchase reference.
dpreview.com has everything about digital cameras: digital photography review, news, reviews, forums and FAQ. Especially the reviews on almost all the famous models are fun and comprehensive to read. There are comprehensive comparisons between major camera models, with different parameters, such as ISO values, aperture and shutter speed. One will no doubt feel more comfortable in purchase of a camera after reading all related information.
Bob Atkins is a nice site with reviews, photo gallery of Canon products. Especially reviews on lens are very comprehensive and worth reading.
kurtmunger has plenty Sony alpha and NEX lens reviews
GANREF is a Japanese site with my interesting services. Review of lens (sharpness) are plotted