I think a lot of people use Coldharbour Surreal Estate. But it feels too open and not very pleasing to me.
The problem is the need for a huge open space for craft stations. You want to be able to present these in an organized and easy way for players to find what they need.
Ironically, ZoS is probably hurting the sales of their premium homes because of this since many of them would make great guild halls but with an inability to decorate within furnishing limits or provide a sensible crafting area, they aren't really functional for that.
Finding space isn't really a problem, finding a house where you can give up half your slots for a house is if you also want to decorate it. I had my original guild house in Earthtear Cavern using murkmire stone platforms to build a large area at the far end of the house (in the water). I then moved to the Ayleid Ruins house and built on the water there, with the pre-made structures in the house carrying most of the decor. I've done Stillwater's for the holiday and they fit pretty snugly on the frozen lake without needing to use platforms underneath (yay!). I have a few other houses I will move to next and they are all pretty decent for constructing platforms. No need to use Coldharbour unless you are on a budget - which is not a great spot to start as you've got an expensive project ahead of you
Moonsugar Meadow is another good one besides Coldharbour, for guild houses, and the atmosphere is nicer, imo. But the difference is that with Coldharbour you can set stations more or less directly on the surface, but in Moonsugar, you'd need to put some platforms first because the ground isn't flat.
I think a guild home should be something unique. The best guild houses I have visited have all been custom built so I suppose I'm suggesting the homes that best lend themselves to custom, open plan designs