I went through 5 in 5 years, but this one has stuck because of tone, function, and, a bonus, offers battery power. It's simple and nicely transparent.
Fishman Tonedeq-TC Electronics Flashback Delay-TC Electronics Ditto X2-Boss TC3 tuner (optional)
The only board here is the one the delay and looper are mounted on. I quit using "proper" boards a few years ago, but keep 1/4" plywood, Velcro, and rubber bumpers around for making small modular boards.