I really don't care about build a level games like LBP. Everyone who makes a level just ends up with a LBP level and the game itself isn't that strong. If you want to make a game get YoYo Game's Game Maker for PC/Mac. That's what I use.
As for creation tools, Halo Reach has the best. I built a reproduction of Goldeneye 007's Facility level and although the colors and textures don't match it feels just right. I'm hoping Halo 4 adds even more to Forge.








