Do 당신 consider that Fullmetal Alchemist: Brotherhood has a happy ending?

No. I did not like it.

That's FMA LOL tragic but i heard Brotherhood's ending is 더 많이 optimistic

Well I was sad that Ed 로스트 his alchemy ... but I guess it sort of was a happy ending. ^^

How could saving the earth, getting your brothers body back, getting married to the 사랑 of your life, and having two children, be an unhappy ending??

The ending of FMA was kinda sad. Brotherhood had a happy ending; Al got his body back, Ed got his arm back, Scar is a good guy now, Havoc can walk again, Roy can see again, and the hominculi are defeated.
Id say thats a good ending. ;)