You should be good with the North Shore. Hit Northstar (ride the back side), Ride Squaw all sorts of options there, and take the lady to Homewood for a day. I suggest staying Tahoe City over Truckee. In TC you're down by the lake. It is pretty sleepy, but there is still plenty to do.
South Shore is fun, but second-rate Reno is pretty much what you got there. Heavenly is ok, but just doesn't get the snow that Squaw gets. Heav is very big and spread-out, but just eh riding. The views are gorgeous and, while Homewood also offers lake views, Heavenly's are from a more elevated perspective (2200 ft higher) and they also offer a pretty cool desert view. Kirkwood is always worth the drive and usually gets much more snow than most other resorts. It is also a long, windy drive (Though I LOVE the drive) from South Lake.
Sierra is much more low-key, but good tree riding for sure.
Traveling the States and Taking Pictures