They can change their power level to match the others. I'm not sure if you have seen it, but if you did: remember when Piccolo was teaching Trunks and Goten to fuse? Trunks was more powerful because he was older and they had to make his power level match Goten's.
The linked video explains it a little (start at 0:1:30).
goku, because he is always more powerful than vegeta,and because, vegeta is never fights for something or someone ,so the more emotional the stronger _____________________________________________________________ Vegeta is very powerful, but Goku wins.
Vegeta is one of Goku's closest friends, by the end of the series. At the start he is bad to Goku, because Goku is more powerful than he is.
Goku is more powerful than Vegeta. This is a continous sore point for Vegeta throughout the series. It is only at the end that he finally accepts it. Saying that though, Vegeta is the 2nd most powerful character in the series. Despite Gohans greater potential, he lacks the drive to train that Vegeta and Goku do, so they will always outclass him.
VEGETA
He's more legendary, but not as powerful. Maybe SSJ4 Goku is, but that is not certain. He's definately more popular than Broly. The fusion of Goku and Vegeta, is immeasurably stronger than Broly though.
When goku and vegeta first fought goku had to use kaioken x3 to keep up with vegeta but on N amek goku had reached truly great strength most sayians cannot reach and also goku became asuper sayian first and when goku fought majin buu vegeta admits that goku is the best actually he only used it to win not to keep up he wanted to use it to surpass vegeta they were tied in power at first well almost tied
Because he is too awesome!!! :D.Seriously now he is stronger because he managed to transform to Ascended Super Saiyan aka Super Saiyan 2 while goku couldn't achieve that at that time!Of course later in the anime goku becomes once again stronger than everyone else. Gohan isn't stronger anymore because even though he became ultimate and beat the crap out of super buu goku managed to go ssj4 while gohan lost some of his powers in gt because he stopped training.
He could because goku has more strategy and vegeta is brute force but their power levels are the same
It is generally accepted that Goku is the strongest single character on Dragon Ball Z. If combined, Vegito, which is a combination of Goku and Vegeta is more powerful than Goku.
Goku of course but I'm more of the vegeta fan
Goku b/c he is more stronger than Vegita
Because Vegeta was under Babdi's spell and told Goku he would kill more innocent people if Goku didn't fight him.