I agree with what John said. Particularly in being dismissive about splitting hairs with image quality when picking a camera. Any DSLR will do much better than what you are used to, and the variety and niche differences in the cameras may be more important to your shooting style than what little difference there may be in image quality. Full frame for example will always be heavier and bulkier than an APS equivalent, and probably more importantly: cost thousands more.

The image quality produced at even the bottom rung of DSLR can still be used in most professional situations, if that tells you anything about image quality.

Some features worth considering:
Video Recording - note that most video capable DSLR do not have the ability to autofocus while recording.
Live View
Dual control dials, more on the fly switches and tactile interface.
Viewfinder brightness.
LCD brightness and resolution. This makes a bigger difference than most would think.
Image Stabilizer options: In camera or in lens.
Build quality/Weather sealing.

Now don't go off and buy a DSLR only to pair it with a junky lens, thats like building a nice fancy hot rod then putting a Honda Civic motor in it.