Depends on what you are looking for. If a real qwerty keyboard is a perk for you, the only one which is any good is the LG ally's.
Kind of wish I didn't buy an iphone.
I have an iPhone 4 (Company pays for it) and just got rid of my Moto Droid, which I miss ever so much. Do some research ahead of time and find out if the phone is going to be rootable. If you can't root the phone, you're really missing out on the whole open source experience.