I would love to see Jetfire and Shockwave but trademark issues would probably hamper Jetfire. But the Pretenders would be on the top of my list. My old set is getting that sticky tackiness shell syndrome.
You all remember G1 more fondly than I do. I was a kid in the 80s and the G1 toys were B-A-D.
The new toys based on the same characters are MUCH better, even if (because?) they don't have die cast metal parts. Bring on the new, re-imagined toys with modern engineering. I'll take hollow arms over brick-bots any day.