I’m very fussy about performance and script. If I consider the writing to be bad I’ll give up on TV very quickly. I abandoned The Expanse after five minutes. If I’m watching with someone else I’ll probably give something slightly longer, bailed out on True Detective Season 2 after twenty minutes. But if something is of an acceptable quality but just isn’t grabbing me I’ll probably watch up to two episodes before giving up.
I hardly read at all these days but I’ll give up on a book at pretty much any point if it starts to disappoint. I always flick through to gauge the quality of the writing so it’s likely to be plot or characterisation that makes me bin it.
I know you didn’t mention film but I’ll bail very quickly for poor writing/dialogue. I sacked off the X Men origins thing about Wolverine after about four minutes. Also happy to give up at any point thereafter, didn’t bother watching the last twenty minutes of the first Avengers film, for instance, because I figured the goodies would win and couldn’t be bothered to watch people throwing buses around any longer.
Don’t play a lot of computer games and am difficult to hook. Last game I played all the way through was probably Red Dead Redemption or Portal. About ten to twenty minutes is probably enough for me to know if it’s the kind of game I’ll enjoy.