By B-Tier anime I mean anime that is "average", nothing that you would consider the best-anime-in-the-world, or so-bad-that-is-good, or something that you would have strong opinions about; but animes that are just "ok" but can hook you up from start to finish.
The best that would fit this category for me is Uninhabited Planet Survive, which is about some kids in the future who get space-shipwrecked in an unknown planet. The premise is so simple but every episode is enjoyable and have a decent overall story.
It's not the best anime in the world nor it tries to be (it's mostly aimed for children), the animation is ok, the soundtrack is nothing special, and the characters aren't very original but they feel real (every one with their own flaws).
So, it was an interesting experience for me to find an anime that fit this category, and I would love to read if anyone else feels the same with any other average anime.