Probably Galactus, though topics like this are strong in Nerdrage and could be debated endlessly in comics forums.
You didn't ask, but in DC ... I'd probably go with the Anti-Monitor.
i have to go with carnge
clayface
Modern Marvels - 1994 World's Strongest 12-40 was released on: USA: 18 October 2006
Modern Marvels - 1994 World's Strongest II - 13.16 was released on: USA: 23 May 2007
Kid buu
Kid Buu
No, Megatron is not the strongest villain of all time. On the list of strongest villains, Megatron is 68th.
He is not really a super villain, he is an anti -hero. He is just crazy, and yes. Because if I can put myself back together after being blown up, I am the strongest ever.
Norman
Currently Whis "Dbz Battle Of Gods"
yes but remember when he was transforming from super buu back to kid buu he was real muscly in 1 form that is actually his strongest state
Dock ock,venom,mystirio or scorpian but mostly dock ock he's mint
No. That honor would likely go to Galactus, eater of planets. Or perhaps Onslaught.