I honestlty think that the Hulk alone could beat Doomsday- he doesnt need Jugeernaut's help. Remember that there are alot of extremites that Doomsday mentioned when he was fighting the alternate universe superman (Justice Lords) that the Hulk can survive as well. Not to mention on top of that, that Hulk has the greatest healing factor in all of Marvel. Superman needs the sun to regenerate and heal- the Hulk doesn't. I'm not sure what it will take to kill Doomsday but I'm sure the Hulk has the endurance and durability to last long enough to eventually figure it out. On top of that Doomsday has a major flaw that the Hulk doesn't- his weakness is green (Kryptonite). They said in the show that Doomsday was created from Superman's DNA and although he was made to be his superior, he still has the same weakness as Kal' El. Supposing that the Hulk had Banner's consciousness, it wouldnt take him long to figure it out and capitalize on this weakness. Also, though Doomsday can't be beaten the same way twice, his strenght level is static- he cannot get stronger than he already is. The Hulk can- the Hulk has never been enraged so that his strength in its entirety has ever been revealed- Doomsday may be the one to push the Hulk to the extreme. Doomsday may not be able to be beaten with the strength-level of superman's punches but if the strength level of the Hulk surpasses the strength level of superman, he could beat Doomsday. If the Hulk becomes stronger than Doomsday, Doomsday is finished. I dont see how it can be the reverse- Doomsday beating the Hulk into submission to the point that he is either too weak or he returns back to normal. The main characteristics of the Hulk is the 'madder he gets, stronger he gets with no limit' and his accelerated healing factor.