I had made a fair amount of tile-based level editors before the .tmx importer came around.
This one was in C2..what a nightmare.
<img src="https://dl.dropbox.com/u/105711543/Images/Editor_WIP.png" border="0" />
This is the biggest one I made in CC..Was pretty cool because you could rotate tiles & objects, and groups of tiles like big tetris pieces ( Thanks again tulamide ). All objects and properties, tilesets, and BGs were chosen in the list boxes. There were also extra properties like "highlight current layer", zoom, scroll speed, and a drop-down menu to choose level properties like music.
<img src="https://dl.dropbox.com/u/105711543/Images/CC_Editor_WIP.png" border="0" />