I'm a really big Yugioh, Soul Eater, Fullmetal Alchemist, and Attack on Titan fan!
Thoughts on Attack on Titan: Never has an anime immersed me so deeply in a story before, not even Fullmetal Alchemist. The animation is breath-taking, the characters are terrific, and the whole anime is a thrill ride of action and sorrow...
Any flaws I see with Attack on Titan are overshadowed by the power of the visuals and the voice acting.
Personal opinons on my favorite animes:
Attack on Titan > Kill la Kill
Fullmetal Alchemist (2003) < Fullmetal Alchemist: Brotherhood
Fairy Tail < Soul Eater
Amagami SS > Monster Musume