3. Thanos
Sticking to the idea of evil cosmic space gods, we get to what is basically the Marvel version of Darkseid, Thanos. Well known in the comics community, Thanos became very popular in the wider world after his post-credits cameo in The Avengers movie. Often called The Mad Titan, partly because he grew up on Titan, one of Saturn's moons, and partly because, well, he's hella crazy, Thanos' character is defined with his pursuit of love in the form of Mistress Death. That's right, instead of world domination, absolute power, etc. he desperately wants to have his way with the utterly terrifying being, Death. That's why they calls him Mad! The best Thanos book is Jim Starlin's classic The Infinity Gauntlet where Thanos is collecting the Infinity Gems to complete the Infinity Gauntlet and wield immense power, leading to him defeating every hero in the Marvel Universe and threatening all life everywhere. And why? Because he wants Mistress Death to be his girlfriend! Incredible but true. It's an amazing book, go and check it out. Besides almost destroying everything and failing, Thanos has the essential super-villain quality of never giving up and has tried destroying the universe time and time again. Thwarted a few years ago during Dan Abnett and Andy Lanning's run on Guardians of the Galaxy, he has recently returned to headline Jonathan Hickman's Infinity which looks to repeat Thanos' plan of obtaining the Infinity Gauntlet to raise havoc. Nothing says crazy than attempting the same thing over and over and expecting a different result every time. Thanos ticks most of the boxes you would expect in a cosmically powerful super-villain super strength, stamina, he can absorb and project cosmic energy, is telepathic, and can throw a pretty mean punch. He's also a genius (there's no such thing as a mega-stupid super-villain) who builds some great devices, my favourite being the transportation chair that flies him through space. A flying chair what's not to like? Plus he's pretty damn scary - look at that mug!