I'd like to see Rockhold vs Bisping. I don't think cardio would be an issue for either guy. Rockhold has gone 5 rounds a couple times recently. Would be an interesting fight. Rockhold has a well rounded ground game and is very hard to get and keep down.
I'd also like to see Belcher vs Carmont at this point. Belcher has been a disappointment and I think he would be a perfect person go gauge Carmont.
Miller vs Masvidal just sounds awesome to me. Both guys are tough as nails and love to go at it.
I also think it's time to see Bader vs Davis. They have both had mixed results vs top guys and I think it's a good fight to see where both men are right now.