I've been an Altmer mage through four characters (4th still going), now I'm trying a Breton on an experimental playthrough.
I have to say, I don't like being SHORT!
Kudos to the game mechanics, that actually convey the height difference even though the characters aren't in the same game. It is palpable!
I did feel that my Altmers were stronger in battle early on (when the playing field was more level).... using magic or weapons.
Other than those two, I haven't tried other races.