Peter Parker/Tony Stark.
I know, slash pairings like these would never happen, but damnit, Tony was so Peter's sugardaddy/big brother all in one, that I would love to see them together again.
Xander Harris/Andrew Wells
Even if only to show that the Buffy s8 comic can give us naked boys sleeping together, as well as naked girls
Buffy/Spike/Angel
Because it brings my two fave pairings, Buffy/Spike and Spike/Angel together and might actually succeed in making all three of them happy.
Captain Jack/Rose/nine
Because those still have the same chemistry that they did back when I first saw them together.
May Parker(Spider-Girl)/Jake Grimm
Even if only to see Peter's reaction when he finds out his daughter is dating Ben Grimm's son.