vegeto vs Thor (normal)
I think Thor would win, not in speed, but in a variety of powers, including strength and only flight speed.
Vegeto strength was never shown, but he chose to move out of the way of Buu's attacks to keep from being hurt, so he wasn't invincible and could actually be hurt. He also showed no resistence to transmutation, so Thor's magical abilities, which are different from ki attacks, will pose a threat to him.
Strength was never displayed by vegeto, but that doesn't mean that because he has no feats of strength to show that Thor can't beat him. Thor has strength feats greater than both Goku and Vegeta combined, if you put both together they still wouldn't reach the level of strength Thor villians possess.