I'd recommend fullmetal alchemist brotherhood, it is actually better than fullmetal alchemist thogh they are both amazing!
Also, they're not similar but you should watch High School Host Club, its very funny and has its romantic parts too

D.Gray-man has the same kind of humour and action scenes and a good plot so I recommend that along with Vampire Knight which is doubly amazing.
I've been told that Code Geuss and Darker Than Black are good if you like Fullmetal Alchemist but have not watched them myself. Hope I helped!