From your experience what models tend to be in the highest demand? the least?

I'm still working on getting a good workflow going, but I've put up a few models already. I've noticed that the models that I thought would get more views haven't, while some of the ones I thought wouldn't get a lot... are getting a lot. From your knowledge, what are the kinds of things people search for the most? I know I'm asking a lot, but also, are there some types or styles of models that tend to sell for more than others?