The anime series Fullmetal Alchemist definitely deserves a 10/10. That series was just fantastic and will always be my favorite. The show itself had a fascinating storyline and very interesting characters. Even though most of the series had a heavy tone to it, comedy found its way in. I like when serious shows can also be lighthearted at times.
Btw, I am talking about the original 2004 anime series of FMA, not the recent redo of the series titled FMA: Brotherhood. I haven't gotten a chance to check that out.