I personally have the Droid 2 Global (basically the same as the Droid 2, but with a GSM transmitter [SIM card] along with a CDMA transmitter and a faster processor, at 1.2 GHz compared to the 1 GHz found on the Droid 2), running a custom ROM called Fission 2.4.3.
Of course, if you want a phone you want to be able to modify entirely (kernel and all), don't go for Motorola, go for HTC or something.
Oh, and Android has Flash Player, which is really nice, and something iPhone users will never get.