I use a 6wt most often. 1 to 2lb bluegill are quite common in the waters I fish most for them and those waters also have a lot of brush, stickups, tules to get wrapped up on. Too many fish hooked on 3 and 4 wts have been lost in that type of structure. I run into quite a few bass also in the same water.
My favorite rod currently is a St. Croix Premier 7'6" 6wt.