OK, I got a XA, M2 and a M4-P, a Zeiss Contessa and a little Welti 1 for my small cameras. The XA is small and very useful, the Leicas are larger and also great, but for sheer joy of using and looking at; my favorite camera (today) is my little Welti 1.
You said "favorite" not most useful remember.
Yes, tiny viewfinder, fussy film advance, remember to set the shutter, remember to set the focus. Ergonomically this camera is wretched.
But, a coated f3.5 Tessar lens set in a compur shutter looks like a jewel and is remarkably sharp. Folds easily and opens with a snap. More basic than a M2, not that much bigger than a XA.
Usually inexpensive.
I like the look of the little thing, beautifully made, and it shows. This will be my favorite camera.