| Myotin |
There are also several situations that are "social" but can't be thwarted by simple skill rolls: the party is asked to judge a beauty contest (for half-orcs), an olympics style competition is being held (in the third level of a dungeon), members have been summoned to act as jurors (to a goblin court, and the defendant turns out to be known to them), a sphinx has three riddles and will offer a fabulous prize if completed (but doesn't remember them, only their answers). The aforementioned can be used with or without the twists, and can be inserted just about anywhere.
I also have used repair requests (fix my lair and I'll give you a map to the rest of the dungeon), games of chance (actually play them with authentic looking cards or dice), "pet" grooming (a wyvern), and runaway buggies (was that filled with food or did we hear a baby in there?). Again, all can be used easily with humanoids, and with a little imagination, with anything that can communicate (has intelligence).
And in case you are wondering, alignment isn't a problem. These creatures can be atypical, young enough to still have unformed moral structures, or simply be so motivated by circumstances they are behaving out of alignment.
Ever helped a widowed beholder nurse it's young in exchange for the magical cloth needed by local galeb duhrs for a once in a millennium party game? My players have.