I use a Netgear R7800, running a release build of LEDE Reboot 17.01.2, and am happy with it.
It’s a powerful WiFi router, lets you load your own Linux on it, and will turn on WiFi once you do. And it has a recovery mode which lets you unload your own Linux if you mess up and put something on it that breaks it.
This was hard to figure out: I read a whole lot of forum threads that talked about discontinued routers, or routers that worked once but were now locked down, or routers that only worked in Europe, and then one forum thread that was enough to make a decision.
It took a couple hours in total, and that was with having some idea what to look for since I’d worked on WiFi for a few years. If I hadn’t, I’m not sure I would have gotten to an answer at all. (Anecdotally: I tried and failed to find an OpenWRT router once before, four years ago, and bought an Airport Express instead. I think I’ve changed more than the way the Table of Hardware works but it’s hard to be sure.)
Setting up the router with LEDE was straightforward once I got past this, and it’s been running smoothly for the past week.