Does Saturn have enough density to count, though? I mean, from a certain point of view, it's more of a spheroid of hydrogen with a bit of helium. Maybe we need a new term for it, like "Planetary nebula"? ;)

Certainly, Mercury, Venus, Earth, Mars, and Ceres are rocky planets. And Pluto, Eris, Makemake, Haumea etc are icy planets. But the idea that there are gassy planets is just silly.