I've been looking for a small keep to have a player home hidden in the forest. Maybe in Falkreath or The Hold, but I can't find anything. Nothing big. Just a basic foyer, bedroom or two, small library, and a small armory. A stable and/or outdoor forge would be phenomenal. Gardens or something would also be nice to liven the place up. Having a steward and/or a couple of guards wouldn't be bad either lol.
There's no end to humongous castles with extensive battlements, armory rooms, throne rooms etc. Those never interested me; they just seemed large and empty.
If you need any more details let me know! Otherwise just get creative with it!