Doomsday.
He's able to adapt to any threat, lethal or non. He doesn't have to die to evolve past an attack but that is the most conventional way for him to do so. Unlike Hulk, Doomsday has no internal organs, while he's displayed at least some brain capacity....no one can sufficiently knock him out. Doomsday has a healing factor on par or above the hulk and was able to recover from being nearly cut in half within two panals. Doomsday is at present, times stronger than superman, he has shown himself capable of dismantling superman physically with minimal effort and nearly no injuries, putting an enhanced superman using a combination of all of his powers almost completely on the defensive doomsday has a fighting speed that's been comparable to flash. Doomsday's said to be able to surive a nuclear explosion no problem and can generate enough force to hit with the equivalent of said explosion. Doomsday can absorb solar radiation like superman and store it as a battery for up to 1000 years. Doomsday, is also able to secrete poision from his claws that can make superman dizzy...he can also launch the knuckle protrusions from his fists with enough force to break through supe's skin and retract the protrusions like a fishing rod.
...and then of course...doomsday, can recover from death itself, evolving past whatever killed him in the first place....so far we've seen doomsday die by; physical strength, the end of time (being torn apart, since he has survived the end of all things,shouldn't he be immune to everything?), pure energy, de-evolution into primordial ooze, and disintegration.
Hulk.
hulk has a common base strength of about 100 tons, yet he has shown too be able to start at a base strength of much higher levels based on need and anger. the madder hulk gets, the stronger hulk gets. hulk has the capacity to reach unbound strength levels, but he usually needs time to be able to do so. Hulk sports a healing factor that varies from time to time, but overall can recover from being melted into bones within a minute or slightly more. It has been said that hulks skin appears to be unpeirceable, but it's just that hulk heals so fast it simply appears that way. Hulk also has varying personalities, the personalities vary in strength from hulk to hulk. Hulk's strength and healing factor come from a pocket deminsion. this means that hulk doesn't require food nor sleep to store energy....his energy source his arguably limitless.
In short. doomsday's much more lethal and durable with more overall powers. Hulk has limitless potential for strength and is f***in crazy.
......this guy next to me is pissing me off. "F*** THE SPACE TIME CONTINUUM!"