I voted Altmer because they have the most magika with the Antronach sign. Now that we dont' have Birth signs in Skyrim, not sure who will have the most now. While Bretons can be easier to play,
with the magika resistence, I found it way to easy and borin to play with Breton and the Antronach sign, so I played as Altmer with Antronach to make it a bit more harder to play.
Breton and Antronach birth sign makes the game alot easy in Morrowind and different in Oblivion. So I like Altmer, and prefer them now.