Fullmetal Alchemist is unlike any other anime that I have ever seen. If I could have, I would've rated it a 20 instead of a 10. It was incredible. The story line was great. The idea of alchemy makes me wish that I could leave my world and jump into their's.
Although, as an anime for beginners I would recommend watching something else first. Parts of it can be creepy for people who are easily scared (not that that is a bad thing). For instance, the homunculus Gluttony. My (older) sister found him scary, while I did not. Also, parts of it are sad.
Ed, Al, and all the other characters were fabulous. I liked how much the brothers cared for each other. Other than that, it's hard to say exactly why I felt the need to re-watch it over 3 times or why I get nostalgic at the slightest mention of this amazing series.
One thing I do know is that I absolutely hated the ending. It was a total cliffhanger, not to mention sad. It wasn't sad in a way, "Oh no, my favorite character died," No. My thoughts were, "Why did that have to happen?" *frown*. There is a sequel to the series, Fullmetal Alchemist: Conquer of Shambala, but the ending to that was as, if not more, depressing as the series. But it's equivalent exchange, I guess.
Even though I didn't like the ending, Fullmetal Alchemist and Fullmetal Alchemist: Brotherhood were (and still are) two of the best anime series that I have ever seen. I highly recommend giving my favorite anime a chance.