I'd say Ten in Nines leather jacket and jumper in the finale/CIN/xmas invasion. Just worked, and as Tennant was so different to Eccleston, it looked strangely odd but it looked as if Ten could carry on wearing it throughout the show.
Second comes Colin Baker in Davisons, just looked cool on him, might be the hair, i dunno.
I have the Regeneration set of figures from 2005, and the best thing about is, on the Tennant figure, Nines clothes are baggy on him as Ecclestone is bigger than Tennant. There was a lot of thought in that figure. The face is scary though, got a kinda menacing smile and zomby like eyes.