I'm going to ignore level editors for 2d games like warcraft and such so...
First 3d game I mapped for was Quake 1. But basically, those maps were just boxes with enemies in them... first maps I made that could be considered to be 'playable' was for hl1 dm.
TF2 again. I did play with the Unreal 2 editor prior to that, but without luck, nor a playable map to show for it. Now that I have UT3, I plan to start using the Unreal 3 editor.
Age of Empires
StarCraft
Tiberian Sun
Dawn of War 2
Ground Control 2 (probably the most time consuming editor ever)
Half Life and its mods
Half Life 2 and it's mods
I've made maps for Time Splitters but that doesn't really count cause they were prefabricated blocks.
I would love to get my hands on the far cry 2 editor.
I think there are a few other editors i've tried but never really got into because i simply never really got into the game.
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