I had to vote other as well, though if pushed I could change to "617." In my mind there are the S&W K-frame .22s and then the others. Get ye to the local gun shop and prowl the used racks for a Model 18 and 17 S&W. The square-butt frame and lighter barrel balances better and looks sharper than the full-lug models to me.
I've owned and fired Ruger Single-Sixes and lets just say it never left the safe after the S&W came home. The difference is that obvious. I have no experience with the SP-101, but I highly doubt it could make me leave my S&Ws.