I chose Cyanogen because it is the most stable ROM for me. The ones I tried (UD, SS, etc.) seemed to FC on me at random times, and well, I need my Droid to work reliably and quickly for work. Some ROMs, however, seem to work better for others. Different strokes for different folks lol.
Bottom line is, I'm appreciative of all the hard work that these devs contribute to the Droid community--you guys rock!