Versus - Find popular alternatives to anything in a jiffy
Diffen - Compare anything to find similarities and differences. Read, improve or create comparisons.
Productz.com - Crowdsourced products database
SocialCompare - Platform of User-generated collaborative and interactive comparison tables.
Kimovil - Compare price, specs, reviews and benchmarks for smartphones and tablets.
GSMArena - GSMArena is an online site that offers exhaustive and up and coming cell phone data.