Human.
Cheers, -- N
We seem to be shifting from necessary to ideal. IMHO the only necessary race is Human, because there needs to be a baseline to which everything else is compared.
Maybe 3.x biased me, but we've had plenty of all-human parties in D&D.I think there's a difference between the races that would be necessary for a fantasy RPG and then there's the races that are necessary for D&D to still be D&D.