I love the coat from Master Alchemist (as evidenced by the fact that I'm wearing it xD), but I also like the shoe clips and the belt. Little accessories like that are fun to play around with.
The FMA items are cool too though, and they don't have to be used for cosplay. The Armstrong sparkles will come in handy for my usual cutesy pink avatars, and I love Ed's pocket watch.
And don't forget Loyal Jay! Very similar to the FMA uniform, for a fraction of the cost (I actually like the pants better than the Roy Mustang pants, that stupid butt-cape thing always bothered me).