Scooby Doo Show Scooby for me, as it was a mix of brave and funny. Although my favourite episode is The Secret of Shark Isle from TNSDM as Shaggy and Scooby are pure cowardly funny. Anything post Show gets a little meh for me as Scooby becomes irritatingly inconsistent- one minute he's brave, next won't do ANYTHING, then he's intelligent, next he's got no common sense... when Scrappy was introduced he seemed reluctant to do ANYTHING untoward. What's New? was alright though, as they pretty much redefined the characters and stuck to those definitions. I can't watch many episodes though without irritating people in my household as the DVD set sings the theme whenever you open the box. Took ages to find it in a store. And for me SASDGAC will never be acknowledged, ever, so I can't judge his personality in that.
For me early Scooby is best as he was a well rounded character- one episode terrified, the next, actively angry and wanting to solve the mystery (I'm thinking the progression from Miner -> Decoy for a Dognapper)