Samsung Galaxy S 4G / SGH-T959V
I've never had much luck with this device.
* Almost no internal storage (an SD card is required, and you will find yourself having to constantly move apps to it).
* Abandoned by Samsung at Android version 2.
* No official builds of CyanogenMod.
* Current kernel (Aries) as of August 2013 not only has non-functional GPS, but it also has a bug that quickly drains the battery if anything tries to use the GPS.
The hardware was very nice, but it was severely crippled by terrible software.