Doesn't Shadar-kai fill that role?
Well, there aren't that many roles left to fill.
TV tropes suggests five races, all pretty much filled.
The Stout: Dwarf, Dragonborn, Goliath, Half-orc
The Fairy: Elf, Gnome, Eladrin, Shifter
The Mundane: Human, Halfling
The High Men: Deva, Half-elf, Eladrin, Tiefling
The Cute: Halfling, Gnome
We even have the Sixth ranger, the Evil (Drow, Tiefling), though D&D seems to lack in "cute" races and mundanes...
Alternately, we could go by primary attribute (note, not just ability score modifier, but how the race is visualized, treated, and what their racial abilities lend themselves to:
Strong: Dragonborn, Half-orc
Quick: Shifter, Elf, Halfling
Hearty: Dwarf, Goliath
Smart: Eladrin, Tiefling
Wise: Deva
Pretty/Social: Gnome, Half-elf, Drow
By that measure, we could use more "wise" races, I guess.