This is something I saw on another board that I don't really post much on, but it caught my interest.

If you were the Big Exec making all the calls on either BW/BM/TF what would you leave the same and what would you change?
Would you still have Megatron transform into a gun?
Would Optimus Prime still be called Optimus Prime?
Would you still have Waspinator as the comic relief?
and so on...

Pretty much all of Beast Machines.

Beast Wars... tame the more ridiculous humor bits, such a bot being flattened to paper thinness and the like.
Possbly more development on the Vok. What were they? What was the point of their experiments? Did they resent the interference of these bots from the future & consider revenge? (Might have made Beast Machines more interesting.)
Where did Tarantulus & the Tripedicus Council come from?

KAM has some pretty good points there.

First of all, I would have gotten a sponsorship from a fast food franchise. The Autobots would have been led by McDonaldmus Prime, a giant red and yellow robot that turns into a restaurant (complete with drive-thru). In robot mode, he would have a rifle that fires energized french fries and a shoulder-cannon that shoots exploding Happy Meals!

Seriously, though, I would have made Megatron transform into something other than a gun. If I had designed it, he probably would have been a Howitzer, or a Rocket Launcher. Optimus Prime I would have left alone, transformation wise. The only change I would make to him would be the color scheme; The blue's okay, but I would have made the truck cab\torso white or silver.

I would also have skipped the leap into the future c-r-a-p from Transformers: the Movie, or at least have ignored it afterward.

As an FYI for anyone that didn't know. When Generation 2 was made they remade Megatron as a tank because they were not allowed to make him a gun. Too many kids getting shot by cops for caring a toy gun.

Megatron looked better as a tank, imho. They should have left the coloring of the original version intact, though, as I seem to remember the tank being green and purple or green and blue. Something like that.

As for Beast Machines? Bleech!