You’ve been put in charge of The Azeroth Breeding Program which was made to repopulate the world after the 4th War. You have the power to make anyone fall in love with any other person to get the repopulation going.
What two races do you mix with your power? Do you want to make the cutest mix? Smartest? Strongest? Ugliest?
I’d mix lightforged dranei and void elves to get the ultimate light and void weilder 
Humans+Orcs
Vulpera and draenei. I don’t even know what I’d want it to look like, but it would be glorious.
I’d mix gnomes and Mechagnomes for more iron in my diet
I volunteer as tribute.
/tentacleflip
Draenei and Vulpera.
All the sexiness of a Draenei… with fur!
Could you imagine the tails? 
Lightvoided Draenelf.
Also if NPC races are allowed my obvious choice is the Gnogre.
So… can I buy you a drink?
wink
Well Lightforge and Void elves cant even touch without causing explosions so RIP their reproductive organs.
I wouldn’t mix any races really just sub races. Trolls+Zandalari. Highmountain+Tauren ect… Mixed races tend to not happen very easily and if we are going for max repopulation it wouldnt make sense. Only race that seem to have easy time breeding with others is Orcs.
Now hol’ up… I didn’t sign up for this…
Draenei and blood elf. My thorough research into the matter shows that it is not only very common but superior to other halfbreeds.
Statement: I am not sure this would count, but I would subject Draenei to light frame mechanization resulting in the ultimate species.
Oh my, yes.
Velves and Belves. They really need to hug and make up, out, whatever.
Lightforged Undead
We’ll need video of that… for the archives.
But neither of us is even female!
That will not help me to mate!
Do not fret my handsome hulkling, you may hold my tentacles while you preform too make it easier for you. I really do not mind. No, not at all.
Hey, if Schwarzenegger can do it, so can you!