Just got the CM 690 Advanced II for my Dad. Problem is their is alot of vibration coming threw the metal of the case, enough to make a nice humming sound. Does anyone else have issues like this with this case? What is the best silent case all black inside and out for say $120 or less?

All cases where the harddrive is more or less in straight contact to the metal will do that. Even most cases with some rubberised grommets will still be somewhat sensitive to resonance, though with relatively low vibrating drives like todays Greens they are often good enough. If the system only has a few of harddrives they could be mounted in 5,25" bays using either some mounting kit with antivibration properties (though the Nexus DoubleTwin is the only really good one that I have come across, good enough to dampen 7200 RPM drives that is). Or some kind of suspension in a 5,25" bay using straps of some sort, which is not too difficult to set up as long as the system doesn't have to be moved around often. There's a huge thread on suspension in this forum.

Or with a case designed for quietness like the relatively inexpensive Fractal Design Define series you can get something that also counters other types of noise by way of sporting inlcuded dampening and not having an open front like most cases do, although having a door can be in the way depending on how often one has to access the front bays. Personally I'm never having a meshed front case again, unless maybe if 20 years from now we aren't using any mechanical parts anymore.