Help me fill a room

I recently ran by the idea of a railroad past my folks and to my surprise, they did not veto the idea of getting rid of an ancient sofa in the corner of our lower living room. If done, this would liberate an L-space along two walls approximately 230 cm on one side and 350 cm on the other. (7' 6" and 11' 4", respectively)

I got to thinking. What sort of layouts would you do with that kind of dimensions? continuous running is a must, but mind you, my prototype would be European, so it doesn't need to fit US mainline traffic. Both the ends of the L would be accessible from two sides, so a dogbone with large-radius ends would be one possibility.

Loco-wise, I want to be able to run European diesels and steamers from 1930s to 1980s (NEM eras II to IV), wheel orders up to approx. 4-8-2 and C-C (most of them about a foot long, max). I wouldn't mind running the occasional American diesel, probably nothing much bigger than a GP38. I do own a DD40X, but don't expect to ever have either the broad curves for it, or an appropriate string of freight.

Prototype-wise, I've half a mind to forego historical accuracy altogether, running whatever locos from whatever eras I like, mostly because being a stickler for detail does nothing to enhance my enjoyment for running trains. Besides, I could still "realistically" run freights to industries just the same, it'd just mean that occasionally a TGV would have to wait until the BR52 clears the platform.

So, how would you fill the available space? I'm fairly stumped because programs like XTrkCAD tend to have really horrible user-interfaces and as such, are exremely hard to use.