I've got the Bayou Classic Double Propane Burner (model) DB250, and love it. Gets lots of wort to a boil VERY quickly. I always do two side by side 5 gal batches, so it's perfect for that. Major pluses are that it runs off one 1 propane tank, and either one or both burners can be used. Even if you only do 1batch at once, it seems 2 burners give you more flexibility to expand later or simply multitask. Also was pretty reasonable at under $100.