Season 8 wasn't too bad. Season 6-7 was horrible, and I don't talk about those episodes too much. WhoBob WhatPants? wasn't the greatest ending for season 5, though, SpongeBob was called "idiot boy" by his Patrick, Squidward, Sandy and Mr Krabs, so he leaves town but bumps his head and has amnesia. It wasn't too funny though, and I barely actually watch that episode again and again, so his friends were a bit harsh in that episode. Season 8 is just under average, but not that mediocre, though people say the show got better in season 9, season 8 was when it got a bit better. If I'd rate this season out of 5, it'd be at least 3/5. If out of 100, it'd be about 69/100. If out of 10, it'd be about 5.7/10.
It has pretty meh episodes, not too good but not that mediocre, I'm not recommending it too much, but after thr golden age, I'd recommend season 10-present.