Editor42 or Battlecraft 1942?

[Diamondback]

Editor42 for ground texturing strictly; BC42 for object placement and browsing, PCO placement, spawners, "tree planting", in-game map generation, light maps generation, water texturing, skybox configuration.

And, huge advantage over Editor42, you can test your level on the fly with BC42 with a built-in option, as opposed to Ed42 which generates a map that can't be tested directly and has to be lightly edited to be able to be tested.