Vegeta arrives on Earth in episode 15 so I reckon that's the first episode he appears in unless he is seen communicating with Raditz.
i noticed that in the first ep of dbz radditz is talking about the saiyans and what they do and when he says this it shows a flash back kinda thing and in the scene there are 3 saiyans radditz, nappa and vegeta remember vegeta's hair used to be brown.
During the Fusion Saga
Episode 207, "Take Flight Videl", while at 150x gravity and vegeta punches him in the face. Hahahaa
gogeta,movie 12 fusion reborn happened sometime after vegeta sacrificed himself as majin vegeta but not before majin buu was completely destroyed
Vegeta becomes super sayian 2 when he doesn't kill Majin buu. When he came back to help goku defeat super buu.
Cosmo first appears in episode 53, "A Cosmic Call".
Vegeta appears in episode 5, and stars in episode 11.
Bulla make's her first appearance in the 298th episode of Dragon Ball Z which aired January 24, 1996... She is not seen again until episode 25 of Dragonball Z GT if I am not mistaken...
During the Fusion Saga
Trunks turns Super Saiyan in front of Vegeta in the episode, "Take Flight Videl".
Goten and Trunks do fusion in fusion saaga of dragon ball-z, after Goku returns to otherworld. They are trained by piccolo. I don't remember the episode number.
Sometime in the last saga of Dragon Ball GT. I think in the last ten episodes.
106 it did not really show it but, when he appeared it was an episode 106....
Dragon ball z arrival of raditz is the first episode and movie
Bardock, also sometimes spelled BurdockBardock was first seen in Dragon Ball Z Movie 1:Bardock The Father Of Gokubardock is goku birth father but gohan is goku adoptive fatheractually he first appears in the episode where frieza talks about how he destroyed planet vegeta and it shows him being destroyedbardockBardock is Goku's father but he died when Freiza destroyed Planet Vegeta.
She was in the very first episode.
when he first was training for the androids to show up. im not sure of the exact episode though
I think that the episode trunks show when he was a baby was episode 150 - 170.they first show trunks with sword and new born baby trunks in the episode when goku finally returns from the planet namek :)