If you can afford it, hands down Lightwave. Great modeller, excellent render engine, plenty of tutorials on the web, great user forums. If you plan to get into 3d, make characters, or even clothing Lightwave is the way to go. As far as generating landscapes and fancy skies, Lightwave can do it too. But it is a professionnal package and thus more expensive, so are upgrades, and you have to put in some effort to learn it, but it will quickly become very addictive.

Dominique Digital Cats Media