Microsoft: Gold Only members can download some Demo's Silver members cant. they pretty much rip everyone off with XBL
Nintendo: Shitty game regulations
Sony: Promotion of their games suck big time. Or they promote one game way too much.
S-E: Their Delays
Unisoft: Lazy programmers
EA: Same deal with Ubisoft
Besthedia: Their programming sux, way too buggy to be release some games yet they do anyways