Generally, I like anything thicker than a lonsdale or corona x > 46 ring gauge, but like unklebill, the length is dependent on my mood. Generally I like the Robustos because my time with them is short and sweet and low maintenance, sometimes Churchills and Presidentes just get a little harsh after about half-way through, then I toss it and it feels like a waste of good tobacco, so I usually stick to Robustos. Man, how many times did I repeat myself repeat myself repeat myself there? :)