This Dan Hinkley collection of Acer sikkimense from Vietnam has wonderful wine red leathery foliage. It does fine in an unheated greenhouse but haven't been brave enough to plant one out in the garden yet!
We picked Clethra fargesii up a few years ago simply because it was a Clethra that we did not have. It's leaf and growth habit is very similar to Clethra barbinervis However it outshines its cousin when it comes to Autumn Colours.
To shamelessly use the BBC Radio 4 "Desert Island Disks Theme" This is one of my Desert Island plants Schizophragma hydrangeoides 'Moonlight'. If I could only have 10 plants this would be one of them! We have a good crop of liners (at the moment)!