My oldest two (7 & almost 3) are in Land's End slippers. They have textured suede on the soles and do not slip on our saltillo tile floors, even when they're goofing around and running. They stay on very well and seem durable. They haven't been ruined by our brick floors, the occasional trip outside or the repeated washings.
They're plenty warm, and the kids say they are comfy.
Dh has a pair from LE also and really likes them. He beats the heck out of them too.
Aimee CageFreeFamily Mama to Quinn 7, Nichola 3, & Simone 5wk
we bought some handmade fleece slippers at a local fair once and the lady who made them suggested putting some puffy paint on the bottoms to make them not slippery. I still havent gotten around to buying puffy paint and trying this but it does sound like a good idea for making any slippers slip-proof on hard wood floors.