There are lots of options, question is which do you need?
Slide-out keyboard? (Droid, Rezound,etc.)
Good development platform? (Samsung and HTC)
Screen size? (Infuse, Galaxy Note, etc.)
Processor speed? (Rezound, Galaxy SII, etc.)
It all boils down to what you want and what you would be willing to give up.
DON'T base your choice on other peoples reviews, as they are not "you" and don't even think like you. I found this out a long time ago with a Blackberry...
Development device (still running strong)
AT&T Tilt/HTC Kaiser 160
Fresh Froyo 8/29/11
Scoot's 126.96.36.199 N50Vc Kernel
Samsung SGH-i997 Infuse 4G, Some form of CM10.1