Quote: "I need a free landscape creator that has pretty good graphic landscapes "
Terragen is free but has a license fee if you use it commercially.
I'm a die-hard Bryce fan. The current version is 5.0, and 5.5 is coming out on May 5 (nice numerical pun on their part), but version 4 was being given away for free in computer magazines recently. If you can locate a copy, I think you'll be very happy with it. Bryce supports more 3D formats for terrain export than anything else I've seen so far.
A freebie that is often overlooked is 3DEM. It takes real digital elevation data (freely available online, links provided in the help file) and produces beautiful 3D renderings. The only export format I can find, however, is the Terragen format.
If you've got a powerful computer and graphics card, check out the 30 day free trial of MojoWorld from Pandromeda (http://www.pandromeda.com). It's the ultimate in terrain -- nay, planet! -- creation. They used it in that hokey but nice-to-look at "Day After Tomorrow" movie where we all supposedly freeze to death. Anyway, Mojo isn't free after the trial but it's a blast to play with.