My go-to is my trust Ikoflex Ia. In fact, I just managed to find a 35.5mm -> 49mm step up ring (took a while to locate such a weird size), so now I'll be able to use the contrast and IR filters from my OM Zuiko lenses with it. The Tessar on it is really, really good and it's a fun camera to use once you get used to its quirks.
I also have this kinda interesting MP120TC that I built. "MP" stands for "mostly printed," as in 3D printed. It's a very good design that has flown under the radar despite being I think far more usable than the Goodman Zone/Goodman Axis. The designer (not me) put a lot more effort into design and testing than marketing, I guess haha.
Honestly I haven't shot it much. But I could see using it for macro photography in particular. The huge flexibility afforded by front and rear standard movements, coupled with my very good 85mm Solinar lens, feels like a match made in heaven for 6x6 and 6x7 macro work.