first off, being a human in the ME universe doesn't seem that bad. you have the option to be anything from pure biotic to pure soldier.
i'd like to say drell, but we only really met one so it's hard to say how he resembles the race as a whole.
the turians seem like a strong and proud race, but unless i missed it, i've never heard mention of a turian biotic. and there don't seem to be many females either (big minus there!).
for me then, being an asari could be interesting ... long lived, strong biotic power, able to use most weapons (read: asari commando units). and given that i don't ever recall seeing a male asari ... well, you get the implication.