number 1
WorldCraft/Hammer
Back in the days of quake there was one editor that totaly rocked. WorldCraft. Later on it was updated and made so that it could be used on half-life instead, and now half-life 2. By putting together worlds made out of blocks with texures, you could build a whole world. I built so many worlds in the quake days and have dabbled recently in the hl days. Iv reconstructed my apartment and designed my future home.
number 2
RPG maker 95
the game ran at 640x480 and had tiles at like 32 by 32. All you had to do was set how big your grid was and then paint the tiles, then you could put characters and put an invisible overlay of event tiles which affected storyline, loaded videos, hanged worlds etc. It was damn cool
number 3
Legend of the Red Dragon 2 editor
legend of the red dragon was a MUD, but legend of the red dragon 2 was probably the first mmorpg. Lord2 had a nifty little editor that let you add your own sections to the empty parts of the world, or even rebuild the world to your own likes. It was very primitive graphically, but had an interesting scripting system that was very flexible.
number 4
WWF Attitude character editor
you could pretty much make anyone although most of it was just texture overlay. Still i made the entire wcw roster
number 5
wwf no mercy
not as good as far as editing the way your character looks, but you had enormnous options for editing how their moves list was. In fact it was incredible what you could do.
number 6
Warcraft 2/Starcraft level editors
Starcraft was just a beefier graphical version of warcraft 2 essentially..well really it had way more compexity as far as the charcter units go, but it was nice to build maps. I always lvoed warcraft 2 mapamking...id design the maps to be huge endevours. I made a few multiplayer maps, but i loved making single player maps. I'd trap a ghroup of ten peons in one place and the goal was to get out of where they were rather then create some war. I experimented on gameplay the most in this one.
number 7
Tony Hawk 2: Dreamcast
I loved the level editor..and it was 3d...i made an enormous pyramid in the center, and again this editor was nice because I could make some incredable gameplay.
number 8
half-life model viewer
while technically this isnt an editor i could at least change the skins of characters and text out what that looked like. I made all my friends in this game and we had clans.
number 9
MilkShape 3d
Eventually i decmpiled alot of characters and even made a few of my own. I made a ninja turtle from scratch..it was a bitch, but i got it working..and boy did it look funny when it was animated.
number 10
Walnut Creek's Quake model editor.
I could make whatever i wanted, the only problem is I didnt have the full version and my characters didn't move. But they looked how I wanted. I made like every n64 character.