Personally I'd rank them like this (best to average): Sex Drugs and Cocoa Puffs, Killing Yourself to Live, IV, Downtown Owl, Fargo Rock City (Haven't read Eating the Dinosaur yet). That's basically the same order I read them in too, just switch Killing Yourself to Live and IV.
I don't know what you mean by releasing them in order, since you don't need to read Fargo Rock City or Sex Drugs and Cocoa Puffs in order to understand the ones released later on.
Hmm, interesting. Thanks for ranking them, seeing as I plan on buying the next book based on how I feel about Sex Drugs and Cocoa Puffs. I didn't mean in order as in series, I meant in order of their release dates. I wanted feedback as to how people that have read all of them would rank them, rather than someone telling me to "just read them in order of their release."