DarkBoy Darkness is an excellent ROM manager for emulator games.
The program looks for all the ROMs and organize them with the menu to quickly convert them in a executable file.

Its installation is simple and the interface is very intuitive. The ID3 system is powerful and fast. It has a wizard. It looks for the games in your list or in the downloading sites. It supports ZIP files, etc.
It is an excellent manager because it is very complete in every aspect. You will notice that when you have it incorporated in your system.