From largest to smallest:
Kaioken x2 Goku vs. Vegeta - Vegeta pretty much dominated the whole fight, and even mentioned that he made his blast easy to dodge so as to not end the fight too soon
Base Zarbon vs. Vegeta - Pretty close to the first fight, but at least Zarbon managed to block an attack from Vegeta
Goku vs. Cell - Goku landed a few good hits, namely the Shunkan Ido + Kamehameha, but Goku was mostly on the receiving end in this fight
Saibaman vs. Yamcha - At one point the Saibaman and Yamcha seemed to evenly trade blows. Yamcha hitting it with the Kamehameha seemed more skill-based than anything, and the Saibaman still managed to leap up afterwards to self-destruct.