Over the past almost four years, I've owned a total of five sopranos (and a Waterman, but it was unplayable), two tenors, two concerts, one baritone, and a guitarlele (which is really a short-scale guitar). Of those, I have three sopranos (and the Waterman), two tenors, one concert (needs repairs, was my first instrument) and the guitarlele left, so, seven, and the Waterman. I sold and re-homed the baritone (loved it, but thought the guitarlele would replace it, which it did not), the KoAloha Opio concert, and the KoAloha LN pineapple soprano. I accidentally destroyed my first soprano, a mahogany ukuMele. I'm likely to sell the guitarlele, even though it is lovely and wonderful, because I spread myself too thin, and I intend to gift the extra ukuMele tenor to my elderly landlady for Christmas.
As for playing them actively, I regularly (at least once a week) play only four of them and typically have one or two that I play daily. Lately, that's been the Famous FS-5 soprano and the Black Bear soprano, previously it was my Barron River tenor that I still do like.
I'm not "done" yet, but I feel that I'm slowly getting to the point where I know what I want. If right now you asked me which one ukulele I would keep if I could only have one, it would be the Famous FS-5G. It's still new to me, so there's the newness factor, but the immense playability and very precise intonation (three times compensated saddle) paired with its sound, volume, and low maintenance aspects (it's quality laminate, though I'd never be able to tell if I didn't know) make this a keeper for me.
While I feel that having experienced so many (by my standards at least) instruments really improved my understanding of my own preferences, and was rather educating, I also feel that it slowed down my improvement. More focus, I feel, is better. Still, seeing how I went through various phases where I favored this or that size, this or that tuning, I think that this journey has definitely been needed, if only to get the wondering and speculating off my mind.
Ideally, though, I'd like to end up with no more than three, and that'll happen eventually. I think I'd feel best with that number.