So I recently got a printer and while I have found plenty of good terrain to print, I know there was a running thread a while back with a list of terrain files that has now fallen into obscurity. I wanted to get that going again to see what everyone has found.

Imperial terrain has lots of good stuff, you gotta pay for the 3D flies tho. But well worth it!

Seconding the vote for Imperial Terrain.

There's also this chap on Thingiverse: thingiverse.com/Terrain4Print/