Hey there irulewithmoles.
Here's a thread where G.I.Joe has already been discussed. Seems Ferret Warlord was working on it, but he's away now and the topic seems to have been down for a year, so it seems fair that someone can take up his work. :)
As for Transformers, I would like to see a TAS of that game, just for the fact that it's so crazy hard! I'm lucky I played it on emulator with savestates, but even so I only got to level 9, after that it just looped over and over again, I still have no idea how to beat level 9 as of now :( I thought the game was really bad though, so there are better games to pick if for a TAS I think.
I would be glad if you were to give one of these games a try, I know it's hard to get how some stuff work with the emulator, but you can PM me if you have any questions about how something works, or you could look it up in the emulator's FAQ. Should you decide to give one of these games a go, I wish you good luck! :)