Full Metal Alchemist is great but I hadn't gotten around to watching Brotherhood (I assumed it was a sequel show like Nurato Shippuden). Currently I am in the middle of re-watching FMA because I couldn't remember the ending. I'll probably follow it up with Brotherhood.
The thing with FMA is this: First series of FMA follows the manga for the first 25 episodes(but pitches in extra stuff, like Barry meeting Ed once before that research lab time, that never happened in the manga) and the other episodes split off from the manga into their own thing.
Brotherhood starts with a random prequel episode4 to FMA that I see more as fanservice, but it's not related to the manga at all. After that they rush to the part where the original anime split off from the manga(They really blaze through the original anime's coverage really fast) and past the split, as far as I've been told, it follows the manga pretty closely.
If you really rewatch the original first, episodes 2-9 of brotherhood will probably feel very redundant.
Also, +1 for Tengen Toppa Gurren Lagann and +1/2 for Code Geass. TTGL is just sheer win, and CG has an amazing first season and a debatable second season(some liked, others didn't, I'm neutral, though I feel it didn't follow the first season as well as it could have)
I heard enough bad reviews of School Days to actually recommend you to avoid it, but I don't yet know if everyone hyping this series is a running gag of the forums or the show really has a lot of fans and reviews misrepresent it(I'm still new to this place myself)