Lobo is kickass great. Immortal, strong, and barred from both hell and heaven!
Dr Doom is the man, and just plain amazing. He'd give Batman a run for his money over who has masterly over prep time,and give Magneto a headache in the power department (even if Mag won).
And Doomsday is a plain nightmare. Strong, fast, and hard to kill. And if killed he comes back stronger and faster, and immune to whatever killed him in the first place.
Great team. But great will not work against their opponents.
Superman Prime: Basically Superman after millenia of wondering the cosmos, and a couple more sleeping in the heart of the sun! And not only this, but he stormed through hell and broke the gates of heaven. And not only that, but he has the last GL ring plus the sword of heaven. Ridiculously more powerful than any superman before, even the Pre-Crisis supes, Prime is the one they all look up to.
War Hulk: Hulk times two. Stronger, more vicious, and a one-person machine of destruction. He made Juggernaut cry uncle.
Cosmic Spiderman: I'll say nothing about him (i can't speak of him without giggling), but he is super powerful. His only weakness is his ridiculous costume!
Any of these three could take on the Lobo/Doom/D'sday team. All three together would just demolish them on a molecular level.