JJ Hardy is fourth or fifth on my own list.
Andrelton Simmons is eighth in fielding percentage. However, he's #1 in UZR (11.3), dWAR (3.1), and DRS (24). And if you cut the three numbers in half, you still have arguably the best defensive shortstop in the league at *half* his numbers. Case in point - fielding percentage can be as much determined by the scorekeeper as it is by the players' capabilities and there are way too many factors to single it out.
Florimon is a work in progress. 27 is not too young to be a prospect by any means. He is learning how to finish plays and that's what's key for him. Florimon is 5th in UZR (5.9), second in dWAR (1.4), and second in DRS (9). Notice how far above him yet Simmons is. Florimon, though, has a RF of 5.9, easily best in the game among shortstops, and that's why I rank him high in the future, whether he's elite now or not.
Tulowitzki is second in UZR (6.5), ninth in dWAR (0.8), and fifth in DRS (5). The most glaring issue for Tulo is injuries, and while it seems like an odd factor to throw in here, you expect the best in the league to play every day. Tulo can't; he's just not got the right genetic makeup.