The bat-winged guys on the upper left are Robots in Disguise Galvatron (the white one) and Robots in Disguise Megatron, respectively.

Thanks. I really wish they would not keep reusing that name. It's up to what, three or four continuities now?

It's up to ten, now.

Transformers Generation 1
Beast Wars
Beast Machines
Robots in Disguise
Armada
Energon
Animated
the live action movie
Prime
and now the new Robots in Disguise series, although I'm not sure if Megatron is in that one, since I'm never watching that show. So it's up to nine for certain.

And I agree, I wish they'd stop doing that.

Plus the new RID comic, and there's a RID comic from a few years back.
MTMTE is in similar shape. There's three that I know of for sure.
I know of more, though some may be part of a verse and I don't see it:
G2
Shattered Glass
Devil's Due (WW2 GI Joe crossover)
Hearts of Steel
G1-Dreamweave
G1-IDW (at least 1 here, likely 2 or 3)
G1-Marvel
Cybertron
War for Cybertron/the current games
Rescue Bots
Headmasters
Target Masters?
UK comics (at least 1, likely more)
G.I. Joe And The Transformers
ReGeneration
Go-bots (depending on who you ask)

Yeah, I was just counting the tv/movie media, I didn't have the patience to deal with everything else. ;3 I didn't think Megatron was ever in Rescue Bots. But yeah, there's also the 'NERF gun' thing he was for a while in the toys.

Oh god, I totally forgot about those. Most of the toy lines are their own continuities too. And several games I forgot about (like the new one).

But yeah, it all comes down to far too many to keep track of.

I've beaten (and have) the new game, Transformers: Devastation, and it's based on the Combiner Wars line of toys that are out (although, curiously, Optimus Prime is his G1 incarnation throughout the entire game. It isn't mentioned that he gets a combiner upgrade until the very end, after the credits), so the Megatron in the game is based on the Leader-class figure from the CW toy line.

As well as the Generations Galvatron they had a few years ago (along with the 'NERF' gun Generations Megatron. ~shudders~) that turned into a small tank.