Considering the ubiquity of bell peppers in recipes and grocery stores, shouldn't we have a forum devoted to them? (A search revealed several pepper threads, but most of those posts seem to be about hot peppers.)
Some have commented that bell peppers are hard to grow. I haven't found them difficult in Zone 6, either in the ground or in 3 gallon (or larger) pots, but they often do appreciate some support.
Of the varieties I have tried, Big Bertha has produced the largest fruit, but they are slow to turn red. Cal Wonder, Jupiter and Merlin are productive but were not as large. For different colors, Purple Beauty has performed better than Golden Cal Wonder and Kaleidoscope. Colossal (not!) and Big Red have been disappointing for me.
I am thinking of trying Quadrati d'Asti next. Anyone have any other suggestions?