Were looking at a pretty cloudy future here. Angle's contract doesn't expire till next year September, in that time a lot can change in the WWE and most likely a lot of superstars will change shows, there will be new ones coming into the WWE, old ones leaving or retiring. My money would be Angle returning to RAW if he at all does return to the WWE. RAW is the flagship show and Vince is desperate for anything that will bump RAW's rating up. Angle I'm sure can do just that.
Rather than debate on which show I would want to see Angle on and why, it may be easier to look at who should Angle feud with if he does return. He's already done big feuds with Cena, HBK, Big Show, Mysterio, Undertaker, HHH, Edge, Orton. Of those, HHH, Edge, Cena and Orton, I could see Angle re-feuding with cause it's been a while since he had a feud with HHH and Edge, so it would look new again, Cena will most likely be the champion always so he could re-feud with Cena for the title, and Orton also changed a lot since he and Angle feuded. So who does Angle have to feud with that is a fresh idea. There are lots of people for Angle to work with that he hasn't done money with, Batista, Hardy (both of them), Kennedy, Morrison, MVP, Miz, Punk, Shelton, Santino. I would love to see Angle feud with all of these guys and hopefully help put some of them over, because at his age and the bridges he burned, he shouldn't expect to be given the World titles, he should be teaching the younger talents what it takes to be main event and maybe once he's earned it by helping them out and putting some rising stars over, then maybe a World title reign.
So really, to me, it doesn't matter which show you put him on, just as long as we get to see Angle again in the WWE, that would be pretty awesome for me.