What kind of riding does your wife like? Is she comfy with drop bars, or does she prefer flat bars? Are you guys planning on doing any touring?
Without knowing any of those answers I'd recommend some sort of steel frame touring bike as a general purpose bike. No heavy/crappy/unnecessary suspension to worry about, relaxed geometry is more comfortable than compact racing bikes, frames are a little overbuilt to withstand lugging baggage so you don't have to worry about anything breaking if you head across moderately bumpy stuff, typically these frames can take wider tires for greater comfort, they've got lots of points to add fenders/racks, wide gearing (usually with a front triple) means easy spinning no matter the terrain, drop bars will allow for a more aerodynamic position and different hand positions on longer rides.
(A hybrid without suspension can also work for most of the same reasons - main problem being the flat bars which don't allow an aerodynamic position or many handholds. If you go this route, it might be worth popping a set of butterfly bars or at least bar ends on the bike.)
As an aside - I'd only favour cable actuated disc brakes if you're planning to use the bike in wet/muddy conditions very often. The main benefit of running discs is the improved response and better control that hydraulics give you over braking - and this is lost with cable actuation. In regular dry conditions there's no benefit between properly set up cable discs and cable rim brakes.