They could make it work the second time around.

I doubt it since Anya's dead! But since Xander can't be with either Buffy or Anya I'd want him to be married to Willow!

^I was thinking of an AU where Anya survives. Cordelia is also dead by the end of ATS but she's another option here.

Neither Buffy or Willow would work since Buffy and he are more like siblings by the end, and Willow is gay (I interpret her as bisexual, but officially she is gay, and even if they stated she was bisexual the writers would probably still choose a female love interest for her).

Xander and Willow all the way!