The 7D, 60D, 550D & 600D all have the same 18MP APS-C sensor. The best value Canon crop sensor DSLR today is the T3i/600D. It has the articulated screen, manual audio levels & the very cool 3X crop mode zoom.If it were me I'd get a 60D instead- the 7D has the better sensor but it's deadly without the moveable screen- IMHO.
Noah