Have had 19, 21SF, 22, 23, 27, 29SF, 30SF, 32, 33 and 36. Now that I've handled and shot the range I narrowed it down to the models which fill the most niches in the fewest models. I have 5 G27's and a G30SF. The 27's are capable of drop in barrel swaps to shoot 9MM, .357 Sig and 40 S&W and can use the full range of magazines offered for those calibers. They are the most concealable and still lose no significant features over the longer/larger models.
Similarly the 30SF can be used as the platform for shooting both 45 ACP and 10MM and can use all the magazines for those calibers.
I would like to try out a 30S to see if it really improves the carry/concealability over the 30SF but other than that I have no need for other models....except as trade fodder