I would skip all thoughts of carpet unless it's something that's small enough to be thrown in the washer. We like to step out of our beds onto something soft, so we have little area rugs beside our beds.

My first choice would be cork. But that's just not in our budget.

My second choice would be snap laminate. We just finished ds's bedroom in the snap and love the fact that it looks like wood but doesn't scratch as easily. (We got some beautiful flooring for $2/sq. ft. Canadian).

That said, I just put that new tile on the downstairs bathroom floor, the kind that overlaps and glues together but sits on the subfloor and 'floats' like Pergo/laminates. It's very thick and sturdy. I thought of the glue being an issue but decided that I had to err on the side of water damage control (it's the bathtub bathroom where the children play and splash). I rest as easy as I can with this, knowing that we don't really spend much time in the bathroom. It also has a beautiful wood look (dark walnut) and cost $2/sq. ft. Can.