Best 2.1 I've tried is 2.01 + 2.1 apps.
Unfortunately I don't think the best I tried is available any more - it was the v4 of the Birdman ROM, IRRC...and was not restored after Alldroid got hacked a while back.
I would not try the Sholes R1 ROM - lots of issues reported (by me and others) related to growing lag/slow-down, and other problems after using it for a bit.