This may sound like a strange one, but I've been rewatching TNG in hi-def lately, and recently viewed the second season episode "The Dauphin." I would love to see Anya again. Her parting words to Worf that they may one day fight on the same side together were interesting... it would be pretty cool to see her and Worf team up. Similarly, and I may be alone in this, I wouldn't mind seeing Salia again either.
A little unorthodox or obscure, but for some reason their characters fascinated me this time around.