Dr. goodbud, everyone has there own personal preferences on which is the cheapest and which is the best. As its been said, simply build your own. I run a 18g 10 plant bubbler that was incredibly easy to put together. the most expensive parts were the air pump(dual manifold, quad output) $60 bucks, and $20 for the 3 1/2in hole saw for cutting holes for my net cup. I didnt use airstones. I made bubble rings out of 1/4in air line. Once i dialed in my strains choice of nutes, all i gotta do is top off with a gallon of distilled water 1x a week and change my res. every two weeks. It really doesnt get much easier than that.
http://boards.cannabis.com/advanced-...ml#post1557579

http://boards.cannabis.com/hydroponi...r-bubbler.html
that last link just shows the bubble ring makeup i use .