With Froyo (android 2.2): Check this thread out to make it a little easier on you:
http://www.droidforums.net/forum/droid-2-roms/87309-list-all-working-d2-roms.html (ONLY froyo ROMs are listed--hasn't been updated in a while apparently.
As for the features between the Froyo ROMs, check the thread (found in the link I posted above) and skim through it to find the different features. They're all kind of similar, with a few different tweaks here and there.
Basically pick one, and try it out. Once you root and get CWM working, give each a try and find your favorite. Liberty and Fission are most common with people I know/talk to with a froyo ROM on their D2/DX.
There is only one Gingerbread based ROM aside from the stock Motorola Gingerbread leak (as far as I know at least). ZombieStomped is that ROM, and it's pretty sweet. Since the dev's are actually working on it, it's only going to get better. Keep an eye out. (this forum!)
Personally, I'd stick with a gingerbread based ROM. They looks good, runs great, and you just can't beat the battery life with all of the above. A good choice in my opinion. But in reality, i'm sure 99.9% of people would agree that any ROM for the D2/DX would be better than stock.
I only ran Fission on my D2 before going to the rooted GB leak, then to a ROM for the DX (on my D2--didn't work so well

), but now i'm running ZombieStomped 1.2, and it's pretty nice. Waiting for ZS 1.3. New features are always fun
