I would definitely choose the 60D over the 600D (I actually did, in fact). They have the same sensor, but the 60D has a better viewfinder (pentaprism instead of pentamirror, and a swappable focusing screen), and a much more robust interface. (it has other advantages, but that was what sold me) The 600D body is missing dedicated controls for a lot of the stuff you'd want to adjust while shooting. Instead those settings are in menus, or button combinations, etc... And only $100 difference between them right?