Jupiter

In Poul Anderson's Three Worlds To Conquer, Jupiter has a solid surface and ammonia oceans like Babur and T'Kela. See here. In Anderson's A Stone In Heaven, there is a more up-to-date description:

"Jupiter...is primarily liquid, beneath a vast atmosphere; a slag of light metal compounds does float about in continent-sized pieces, but most solid material is at the core (if it can be called solid, under that pressure). The slow downdrift of matter, drawn by the gravity of the stupendous mass, releases energy; Jupiter radiates about twice what it receives from Sol, making the surface warm." (VI, pp. 67-68)

My other favourite sf writer, James Blish, coined the term, "gas giant." From this phrase and from reading Blish's They Shall Have Stars, I had gained the impression that, on a Jovoid planet, the atmosphere just became denser and denser all the way down to a super-solid core. The Wikipedia article says that most Jovian matter is in a state where there is no distinction between liquids and gasses which is an even clearer description of what I had thought.