The 2.5 gallon hefty bags have worked great for me in the past. Even on larger briskets (18-20lbs) they fit.
Shirley Fabrication Offset Awesome Pit
Backwoods G2 Party & G2 Chubby
Big Green Egg XL
Weber 18.5 Kettle
"Tenacious Q" Competition Team, Head Idiot
Follow Tenacious Q on Facebook!!