>>6749439Depends on what you want.
If you're looking for a G1 Megatron, then Maketoys Despotron is often considered the best option for his build quality, articulation, and many faces. Avoid Apollyon at all cost as he's a fragile fuck who will break and chip. Be aware that no 3PMP Megatron includes all his accessories for gun mode, meaning no stock or barrel.
If you're not concerned with accuracy, Maketoys Cross-Dimension Riot Despotron is a pretty banging sci-fi alt take on Megatron, but know he is the weakest of the CD figures. There's also some upcoming Beast Megatron toys. Fanshobby retooled their Fei Long into the Red Dragon which is pretty much a red Doublecross with two new swords. Perfect Effect has a Transmetal 2 Megatron on the way, but you may want to hold on reviews since PE's quality is either near perfect or a complete wreck.
If you want to put the work into a 150 burger figure that has flimsy QC and games workshop grey all over, get pic related. Gladius is a pretty great idea for a Triplechanging Megatron with a good number of accessories, but Bold Forms never puts out good quality figures, so you'll need to simultaneously loosen and tighten joints all over. He's the Megatron I'd love to get and desperately wish I could recommend, but at his high price, there's excuse for how much work you have to put into him to be tolerable. He might as well be a model kit at that point. Still, he's guaranteed to go for dirt cheap before years end, so he might be worth it at 30 odd bucks.