What's a hero without a great villain? Whether they're out for revenge, money, or world domination, Marvel Comics is full of them. But who is the baddest of the bad?

The Top 25 Marvel Villains 26 IMAGES

Check out our list of the top 25 Marvel villains ---- and then let us know your favorites in the comments!

25 M.O.D.O.K.

24 The Abomination

23 The Enchantress

22 The Sentinels

21 Viper

20 Lady Deathstrike

19 Annihilus

18 Ultron

17 Galactus

16 Kang the Conqueror

15 Bullseye

14 Venom

M.O.D.O.K. is a multi-purpose villain in the Marvel Universe. He’s an enemy to many heroes, especially the Avengers and Fantastic Four. His master plans can be fiendishly brilliant or laughably silly, and sometimes both at once. There are even multiple versions of MODOK floating around the Marvel multiverse, including M.O.D.A.M. (Mental Organism Designed for Aggressive Maneuvers) and M.O.D.O.G. (Mental Organism Designed Only for Genocide).Though he’s largely been out of commission in the Marvel U. lately, the Abomination remains one of Hulk’s most iconic foes. He was the natural choice to oppose the Jade Giant in his most recent movie.Often accompanied by her hulking bodyguard, Skurge, the Enchantress is a force to be reckoned with in Asgard, Midgard, or any of the Nine Realms.As we’ve seen from various alternate future storylines (like Days of Future Past and its recent movie adaptation), these robotic hunter-killers will remain a threat long after the likes of Magneto and Mystique have died away. As long as humanity fears mutants, there will be Sentinels.Viper has also enjoyed a big mainstream boost in recent years thanks to recurring appearances in the TV series Avengers: Earth’s Mightiest Heroes and Agents of Shield and her role in the movie The Wolverine.Deathstrike is one of Wolverine’s best villains because she always gives the old Canucklehead a run for his money. Neither fighter has been able to kill the other, but they’ve both drawn plenty of blood. Their rivalry also made for what is arguably the most memorable fight scene in all the X-Men movies.Annihilus began his career as a foe of the Fantastic Four. But no story showcased the threat he poses to all life like the Annihilation storyline, where he led an invasion force that nearly succeeded in subjugating the entire universe. The galaxy’s greatest heroes have been forced to accept that there’s no stopping Annihilus, only living with the constant threat of total annihilation.Ultron is an imposing villain, by virtue of the fact that its core body is usually built of nigh-indestructible adamantium. And because it can constantly swap bodies and upgrade itself, Ultron is a threat the Avengers will never be truly able to defeat. Which, of course, made him the ideal villain to oppose the team in their second MCU adventure.For Marvel’s heroes, threats don’t come bigger or more dire than Galactus. Earth has been on his menu several times, and only through desperate actions and out-of-the-box thinking have heroes like the Fantastic Four been able to drive him away. Sooner or later, his hunger will prevail.Some know him as the pharaoh Rama-Tut. Others know him as Immortus or Iron Lad. But the one constant with Kang is that he can never be trusted. His ambition isn‘t bound by time or space. And thanks to the tricky nature of time travel, he’s a threat the Avengers will never be able to get rid of.Because of his talents and prestige, Bullseye has long been one of the preferred hired killers on the Kingpin’s payroll. That, in turn, has put him in the path of men like Daredevil and the Punisher. The Bullseye/Daredevil rivalry has persisted for years, with Bullseye claiming Matt Murdock’s loved ones and pushing the hero to cross a line he’ll never be able to return from. For Bullseye, their rivalry is both business and pleasure.Venom has persisted even after being abandoned by a repentant Brock. It found new hosts in the form of a mob boss’ son, the former Scorpion, Mac Gargan, and even in Peter Parker’s good friend, Flash Thompson. Though the Venom suit is being used as a weapon for good these days, it's original incarnation was an incredibly evil monster with a sadistic streak as long as its tongue.