I'd like to see either KENTA vs RVD or Romero vs RVD (Just for the stiff kicks). If Jericho were to wrestle in ROH, I'd want to see him go against Chris Hero, if only for the promos.
I wouldn't mind seeing Kurt Angle in ROH. I still feel he has a couple of great matches left in him, and facing someone like Danielson or McGuiness could be enough motivation for Angle to put on a great show. As far as other indies, I'd like to see Chuck Taylor in ROH, but since he's still young, (about 22 or 23) we'll probably see him there eventually.
The only other wrestler I'd like to see there is Super Dragon... He's wrestled in ROH before during the ROH-CZW feud, but other than that, Dragon hasn't worked for Ring of Honor.