Hey, Matt here. I thought I'd dedicate my first post to the Emperor of Destruction himself, Lord Megatron. First, I'll do a run down of the most significant Megatrons to grace the Transformers multiverse, then I'll have a go at listing them in my personal favourate order.
Generation One Megatron
"Such heroic nonsense..."
The original, and in my opinion, the best, G1 Megatron had it all, from a ruthless, tyrannic rule over the Decepticons, to his position of power ruled with an iron fist. He was also a monster in combat, as well as sporting the first incarnation of the dreaded Fusion Cannon. Sure, some of his energon cube grabbing quests where pretty silly, (lets forget the purple griffon incident), but Frank Welker's awesome voice made up for any flaws his tactics may have had.
Beast Wars Megatron
"Yesssss!"
Now, I know this guy was pretty popular, but I have to say I never really liked him. He wasn't even the real Megatron, just a criminal with the same name later in the G1 timeline. I didn't like his look, or his transformation, though there were two things that redeemed him in my eyes. His ultimate plan to destroy Optimus Prime in the past, changing the outcome of the entire war, and his amazing voice. Speaking of this amazing voice work, we are brought to...
Armada Megatron
"My power is your doom!"
The Megatron I grew up with. This probably does change my overall opinion of him, whether conciously or not, however, I'll try and list why I think he's awesome. First was his voice, the same that was given to BW Megatron. Second was his absolutely ruthless attitude towards the war. (Though, I will admit, he was if anything to harsh allot of the time, but I may only be saying that because of the injustice to Starscream in this series). Lastly, his altmode was an incredible idea, and was heavily inspired by Generation 2, but in my opinion, executed much better.
Movie Megatron
"Even in death there is no command but mine."
Ergh... just ergh. Ok, to be fair, he looked half decent in the second film in the series, as shown in this picture, but that's compared to his abysmal appearance in the first. And it's not just the appearance. He acts like an idiot, and in particular in the first movie, all he does is shout statments such as, "I AM MEGATRON!" Well done, you've finally learned your own name. And even the voice, which Hugo Weaving could have done so well, ends up sounding like a horse, overly deep idiot. What was Bay thinking...
Animated Megatron
"Laugh now, child. I will show you true fear..."
Now, I'm not a fan of Animated. But in my opinion, if there is one thing they got right, it's this bad boy. Some don't like his alt mode being a helicopter, and I have to agree, a tank fits Megatron so much better, but his robot form scream homage to G1, and his voice actually sounds good. He also acts ruthless, but unlike his movie brother, doesn't come across as stupid. My only regret is that he is one of the only propely propotioned Transformers in the whole series.
Prime Megatron
"I am the dominator. I am the destroyer. I am MEGATRON!"
Not allot to be said about this guy, as the show Transformers: Prime hasn't started yet, but from what I've seen while playing War For Cybertron, I like him. His redesign for the show has ruined his appearance abit in my opinion, (head over to the wiki if you haven't seen it), but, this is easily made up for in the fact that Frank Welker is once more taking up the mantle of Megatron for the show, something I have waited far too long for. What else needs saying... ah yes, he's brutal in combat, and is possibly the most arrogant of all Megatron's incarnations.
I've only listed the cartoon versions of Megatron here, and I am aware that I've missed out Generation Two and Robots in Disguise, as well as the other oarts of the Unicron Trilogy. Writing about the comic variants of the comics is best left for another time I believe, as they often vastly vary in personality. (Generation One in particular). And now, I present to you my very hard to decide list of Megatrons...
Generation One Megatron
Armada Megatron
Prime Megatron
Animated Megatron
Movie Megatron
Movie Megatron
Beast Wars Megatron