Fairy Tail is a good purchase. Ended well, and 100 Years Quest is fun so far.
Attack on Titan….I’m sorry, but that entire series is a dumpster fire after the big time skip. I stopped reading it a year ago because I was just so pissed off after every chapter, which meant I wasn’t about to go back and rewatch the anime. I wouldn’t spend any money on that show until you see the ending.
Blood C….most disappointing part of that franchise. If you are going to buy any Blood, get Blood+. Much better.
Honestly, I never buy any series until it’s finished, because half the time they drop the ball with endings and then it’s totally ruined forever on rewatchability.