Skystalker and Sunspot. LOVE that mold, and I do hope Hasbro repaints it a few more times. I'd love a purple Ratbat-themed deco (I'm certain Mindwipe is got to be repainted as Soundwave down the line, Ratbat-Skystalker makes perfect sense), and perhaps a red Laserbeak deco (the mold can pull of a mean "bird-bot" mode).
Of course, Sunspot and Skystlaker play off each other so nicely. Got a yin-yang vibe between them, which doesn't leave much room for a third, fourth, etc..
(Sunny's head is intentionally upside-down, the silver part now acting as a visor, to differentiate from his ro-bro)