This is my absolute favorite episode of the Dragonball/Z/GT series. I just love the fight between Goku and Kid Buu so much. The music is great as well. The action is fast paced and doesnt have as much chatting between the two fighters. (Probably because Kid Buu isnt much of a talker, just a crazy killing machine.) Everyone from the Kais to the villians in HFIL are watching the fight.
At the end of the episode when Goku transforms into a SSJ3, you just can't wait to see the next episode. (Which is also one of my favorites). Watch them back to back.