I'd love to see Theta back at my chapter, Alpha Iota at WashU in Missouri. The Mizzou chapter is so incredibly strong and there's a lot of alums in St. Louis, but no collegiate chapter! (I doubt that'll happen though, because the chapter's already been recolonized once. Sigh) Barring that, St. Louis U (which would be a new chapter), because it's also a good school with, from what I've seen, pretty awesome greek life. (KD, GPhiB, DG, ADPi, and SK)
I'm cosigning with ThetaPrincess on the Southern chapters, plus these other recolonizations:
Sigma, Toronto (the first Canadian NPC chapter ever!)
Epsilon Kappa at Dartmouth (we have almost every Ivy league school covered!)
Gamma Kappa at George Washington (because hey, we need more sorority women in the capitol)
Epsilon Chi at Guelph (I love Canadian chapters

)
And, this is kind of odd, I'd like to see a Theta chapter at every school with both a Pi Phi and a Kappa chapter. Don't ask why, I'm not sure I could explain it