lol, what troll voted for Buu?? not even in his wildest dreams would Yamcha be anywhere near Buu. I don't think he ever surpassed Krillin or Freeza either.

From this list, the ones he can take on at his best are Nappa, Ginyu, and possibly King Vegeta. I would say he can take about everyone weaker than Freeza.

Yamcha, would not be able to defeat many of these opponents - in his prime, Tien was probably stronger than him by a little, even, but he's stronger then, than Nappa was, or King Vegeta... Frieza, or Ginyu? Doubt it.

Nappa!