*lurker chimes in*
I learned modeling on Max, and have used Maya a bit, but my personal favorite right now is Blender for lowpoly and ZBrush for highpoly. At first I moved to Blender because of cost (it is free and open source), but now that I have mastered the interface I actually prefer Blender in its own right. Even though Blender lacks several of the advanced features of Max and Maya, the interface and workflow for modeling and UV is so good that I can modify everything by hand at a low level much faster in Blender than I can click through the menus, choose the feature, set all the parameters, and apply modifiers and tinker with settings in Max/Maya.
There are a lot of little hacks/tricks that you pick up about movement of the viewport, how to select things, setting up efficient groupings of verticies, faces, edges, etc that make modeling in Blender really really fast. If you ever watch the professional Korean Starcraft players with their fast micro and the screen jumping all over the place and hotkeying to switch between all their units, thats what it feels like modeling in Blender once you have learned the UI. With one hand on the keyboard controlling all the settings, that leaves your mouse hand free to only do necessary spatial tasks like moving verticies, rotating the viewport, etc instead of clicking through menus.
Of course ZBrush just plain kicks ass, so theres really no need to explain that choice. Best highpoly organic modeling program ive ever used, it's like sculpting clay.
EDIT: beware though, with Blender the learning curve is steep. I had to read and work through many tutorials before I could even do basic tasks in it (even though I already knew how to model in other programs). Also memorizing the hotkeys is a must if you want to get anything done.