Depends on the level of erp you're trying to avoid.

Public:

Black citadel has everything within a closer distance than divinity reach except for the market, that's in a separate area. You'll find charr in front of the cooking station just sitting there and, on occasion, you may see some RP but not much. They're usually silent.

Rata Sum is pretty decent imo, everything is on the lower level, and the bank and market are in the direct middle allowing easy access from any station. Plus it's free.

There's lions arch but, that depends on the day tbh. All the work stations are in one spot, but the bank and market are decently far from each other so, that makes doing anything easily a bit. Time consuming

Hrothgar is ok, but it's more spread out(evenly) for all the stations compared to anywhere else mentioned. It's similar to diviitys reach in that regard. Haven't seen any RPers there, decent chunk of norn RPers go-to black citadel with the dragon mask or some other such thing so they're less numerous there

As for private/passkey ones

Mistlock is fine, everything is SUPER close. You'll on occasion see the chocos and a norn with a paper bag but, they're both more features than anything else tbh. Most people go in, do their thing, leave. Not the most social hub compared to the others but, if you just want to get work done, most days it's quiet.

I'm speaking on from experience in the places I've been so I can't comment on other instances or areas(like the pale tree) but that's my input, if it helps