I know, I know, "don't start with episode 1", but still, from the first few episodes I slogged through, I thought Gintama was utter crap. Too referential, too forced. I don't care if it gets better around episode 58 or something, I ain't watching 50 episodes just to get to the good stuff, and I'm not skipping 50 episodes of backstory either.
When people ask me if they should watch Game of Thrones, I say "watch the first two episodes, and if you're not hooked by then, stop." I don't tell them to watch the entirety of the first season, even knowing the twist near the end. That's ridiculous. People don't have the luxury of potentially wasting 9 hours of their time like that.