I have seen so many Active Directory Admins use so many methods to find out who and where their FSMO role holders are. Some will use the old fashion way of going through the AD tools and viewing the roles there. Others that have experience scripting have written some elaborate script on how to view these roles.
Either way, I have hands down the quickest and easiest way to view who your FSMO role holders are. All you need to have is the Support Tools installed on the system you are using this on. Go to the Support Tools CMD Prompt and type:
netdom query fsmo
That is all that is needed. It is quick, short and as clean as possible.
ENJOY.