GENERAL UPDATE:
- The list had to be divided into two different posts. From now on, characters from A to M are displayed on page 1, characters from N to Z are displayed on page 9 (a message has been added with those indications).
- The intro message has been removed, since now everyone knows what this thread is about, and the title of the topic is pretty much all that there is to know about it.
- Versions appearing in video games will now mention the different games involved as time goes by. The first game will be used for the name of the version, while all other games that are currently known to have the same version for this character will be mentionned in the description. This won't require "updates" to actually be updated, and I'll add and correct information from time to time, based on my own research and on remarks you might make about "this version appears in that game too".
UPDATE: DEMON KING PICCOLO / GOTENKS / KAME SENNIN / OOLONG / SON GOKU / TRUNKS (ALTERNATIVE FUTURE) / VIDEL
Kind of a manga-related update this time: Tankobon covers, full color pages, limited palette, Daizenshuu artworks...
More updates pretty soon!
DEMON KING PICCOLO:


1) Anime version.
2) Chapter 155 version. A version of Piccolo used in a manga chapter. The kanji and belt are faded purple, with a slightly faded red surrounding the kanji. The suit is black. But more unusual is the use of a very dark brown color for the Namek "muscles" (instead of the usual "skin" tone).
3) Kanzenban version. The Kanzenban collection shows twice that Demon King Piccolo, regardless of his age, wears the same outfit than our Piccolo, with the same colors. The only difference is that he has the symbol on his chest, which is colored as such in the Kanzenban.
GOTENKS:

1) Anime / Manga version.
2) Limited palette version. Gotenks as he appears in the manga the first time he turns Super Saiyan, in front of a small but amazed audience (chapter 482). He's essentially wearing grey and black except for his red belt and ankles. His hair color is slightly faded, as one would expect from a limited palette. Eyes are also dark grey due to the missing green tint.
KAME SENNIN:


1) Anime version.
2) Chapter 106 version. He wears white all over. His glasses have a white border too, but the glass itself has a green tint (the glasses do not appear in this picture right here).
3) Daizenshuu 76 version. This time he wears blue. The glasses have a red border with light green glass (the glasses do not appear in this picture right here).
OOLONG:

1) Anime / Manga version.
2) Daizenshuu 76 version. From an illustration by Toriyama which was used as a poster. The original drawing has gone missing and Shueisha will never be able to use it again, unless they retrieve it from the Daizenshuu itself. Oolong simply sports blue instead of green.
SON GOKU:



1) Anime version. The manga version uses shades of blue that are different from this one.
2) Daizenshuu 3 version. Goku appears to be wearing purple instead of indigo/blue. The scabbard on his back his a darkened yellow. The difference is not so big in the end.
3) Daizenshuu 44 version. From a Toriyama artwork used as a sticker. Goku keeps his red wrists, but now his belt is red too. His clothes show a faded, light blue (not too far from the one used by Toriyama in the full color pages of chapter 1).
4) Daizenshuu 77 version. From a Toriyama drawing used for a daily school schedule (offered with the 1987 calendar as a bonus). Goku wears light blue clothes and orange wrists and ankles. He also has an orange cap, but it doesn't appear on this picture.
5) Kanzenban version N°1. A whole new outfit for little Goku is revealed in the very first Kanzenban. Black on the bottom, greenish-yellow on the up, wrists are almost black with just a little hint of blue, and the tail has a light tone. Later, for the Super Exciting Guide, Toriyama goes back to a look that's closer to the original design.
TRUNKS (ALTERNATIVE FUTURE):


1) Anime version.
2) Manga version. A minor difference is that the suit has slightly more blue, but more importantly, Trunks' hair appear unusually orange in the Super Saiyan 3rd Grade form (chapter 386).
3) Limited palette version. Another case of Toriyama adapting to the color limitations in chapter 386. The eyes and suit are unsurprisingly grey (because the blue and green colors are missing). However, he made the hair pop by coloring them with a faded red this time. Also, the usual yellow of the armor is dark brown.
VIDEL:

1) Anime version.
2) Tankobon 36 version. Videl sports a blue top over a white T-shirt. Note that though the outfit is the same, she has her first hairstyle in the original artwork, while she appears with short hair on this picture.