Agreed! Many games just don't really work well emulated or the cabinet/contoller was what made it. Eg:
Powerdrift (don't think this one is emulated, is it?)
Battlezone (wow I mentioned a game not made by Sega!)
Sega made some wonderful cabinets! No doubt there are many more I have failed to mention.
When it comes to bog-standard shmups, fighters and platformers emulation is fine, but somehow some of the magic isn't there. Whenever I stumble across an old favourite in an arcade, I just have to have a go!