This doesn't even seem like it is an issue. Super Buu is not stronger than Janemba.

Goku as SS3 could fight Buu pretty easily but had a LOT of trouble fighting Janemba. I think if it came down to a 1 on 1 with Super Buu and Janemba that Janemba would win.

geeogree: SSJ3 Goku held his own against Majin Buu and Kid Buu, but not Super Buu (but that Super Buu had somebody absorbed so y'know). I don't recall Goku SSJ 3 fighting Super Buu at his base form though. Regardless, I wouldn't say he could fight Super Buu pretty easily (considering he had a hard time against Kid Buu and that I'd consider Super Buu stronger - unless you want to debate which Buu is strongest [whoa, new poll idea?]).  

However, something to keep in mind was Goku went SSJ3 in the underworld when fighting Janemba, meaning he could sustain the SSJ3 form longer (meaning he wouldn't have to worry about SSJ3 running out for him). Since he didn't have to worry about his SSJ3 running out as much, he could've fought more so at his full SSJ3 potential. 

geeogree : Super Buu is pretty cunning though and has the ability to absorb his foes which is how he took down most of the people he fought, not to mention he can make up for his lack of power with his extreme durability. I think it'd end up being a little more even than you'd think. Akira himself constantly says power levels aren't often the deciding factor in a fight anyway. So I feel like it's only one point out of several that'd need to be determined for this match up.

And Zero makes another good point, Super Buu was much stronger than Kid Buu, not to mention more intelligent and more skillful. 

On the other hand I don't see Jenemba doing much damage with his sword either considering the fact Buu is well, Buu. But it'd definitely be a fun match up to say the least. 

all the power level lists I could find (I realize that Janemba is movie and not manga/anime) Super Buu is listed as drastically lower than Janemba. By like 10x at least but more sometimes depending on the list.

Skill matters of course but I can't see skill overcoming a power difference that big. Especially in the DBZ world where even a small power level difference can make or break a fight.

I have  to agree with what geeo said, Goku did have a much harder time fighting Janemba than he did fighting Super Buu. Call me biased against Buu if you want, but Janemba far more powerful and would obliterate Super Buu in a fight.

Super Buu wins, no contest.

First of all, Goku never once fought Super Buu in his base form (I'm not going to count the battle inside of buu either because that was him and vegeta against a FRACTION of Super Buu and they were really just trying to survive and escape.They couldn't destroy him there.)  

He struggled to overcome Kid Buu who was actually significantly weaker than Super Buu. Because of the fact that Goku was able to overcome Kid Buu with the spirit bomb and even stated he may have been able to destroy him if he didn't want to give vegeta a chance to fight, Kid Buu will be considered slightly weaker than Goku. 

Second of all, Janemba's power levels are completely irrelevant. I don't care what power level lists you saw, Janemba does not have a measurable power level and no source on that will ever be canonically correct. The same goes for Buu as a matter of fact.

While I'm convinced that Gogeta would also destroy Super Buu since even Gotenks had the power to do so, the fact that Gogeta defeated Janemba has no bearing. 

What matters here is that Goku was unable to defeat Janemba on his own even if he did give Janemba some trouble, But could have theoretically beaten Kid Buu on his own. I would rate it something like Kid Buu > Goku > Janemba. 

SUPER BUU IS ON A WHOLE OTHER LEVEL THOUGH. Super Buu was able to hold his own against SSJ3 Gotenks and survived an onslaught from Ultimate Gohan long enough to absorb Gotenks and get the advantage. Ultimate Gohan and SSJ3 Gotenks both eclipse Goku in power. 

Total breakdown in power though, Fat Buu > Kid Buu > Goku > Janemba >  Super Buu > Gotenks > Gohan > Buutenks >/= Gogeta > Buuhan > Vegito.

I would think Janemba would win. Yea Super Buu was tough and all, but Janemba was a monster in his own right. If Super Buu had no one else to absorb and didn't absorb anyone previously, and it was a one on one fight with no interference, Janemba would definitely win.

Janemba that's who I vote for. He has an massive unbelievable and horrible power and strength I have seen. Way far more than super buu to be honest. Janemba is able to do things not super buu can and sup buu can do things not Janemba can do. But what its it more to the point with me is I defiantly see Janemba winning the battle he will win.