Pokemon (The first season is my fav, + the fact that it never ends… Lost track after D&P)
Ooh, forgot to mention. Fell to utter shit for the Black/White seasons (especially the movies), so just skip that monstrosity entirely, but the X/Y seasons have been excellent.
Sword Art Online 1&2 (I love the idea of VR, I hear everyone hate on this one, but it has a really cool story. I’m a big reader, read the novels as well)
I think the main reason is how the first season just u-turned in story entirely. It changed from what was a great action-packed series into some dull uninspired questionable romance. People expected reaching the upper levels to be exciting, and they just opted for time-skips instead. Couldn’t even finish SAO, it just got that boring.