There are a lot of good examples for the best 10 list here given the whole range of S&W collecting. But I thought this was the Antique forum, in which case at least 9 of the best 10 need to be single action.
Magazine pistol is good
FIrst, FIrst, First Model is good
1 1/2 Old Model, 4 in bbl is good
Engraved, Inscribed #2 Army is good
First model American, US, Nickle is good
New Model #3, .38 Winchester Ctg is good
Any single action model in unfired condition is good
First model American, Nashville Police is very good
Heck, any good First Model American is darn good
Revolving rifle is good too
To be fair, finding any of these not already in collectors hands (depending on the quality of the engraved, inscribed #2 Army or First model American) will be like winning the megamillions lottery.