Oh, I've no idea which site you're talking about. o3o; Tho tbh the top manga list is pretty good. I agree with it to a degree. Haven't seen all of Gintama so can't judge its first spot in the anime list
I dunno...if you think Steins;Gate is anywhere near as bad as Sparrow's Hotel or most of the other generic stuff out there, then I have to call your dealer. This isn't even about how you feel about the show, but there are easily 1000+ more generic/unfunny anime out there than Sparrow's Hotel. And Sparrow's Hotel is bad. Real bad. Worse than Steins;Gate.
It's like a bad Western sketch comedy, but anime. It's rushed before its jokes can be developed, the running gags are stupid, the character design is the most generic I've seen...ever, probably. It's bad. Watch it, so you can feel what I've felt.