Napa Valley is absolutely beautiful! They have some great places to stay, you can do some wine tasting, they have awesome spas, lots of fun stuff to do! San Francisco is also a ton of fun...there is too much to list there. Also, Monterey, CA is gorgeous. They have an awesome aquarium there, and Cannery Row is amazing! Check out http://www.canneryrow.com/
Its where John Steinbeck got a lot of his inspiration from. There is a museum in Salinas, if you're a fan. http://www.steinbeck.org/MainFrame.html All of these places are within driving distance of each other, should you decide to check them all out on your trip!
Also, have you ever been to Lake Tahoe? It is on the California/Nevada border. And, it is just beautiful! The lake is amazing, coupled with mountain views! Incredible! If you venture to the NV side, you can even do some gambling in the casinos. My husband and I were married there 5 years ago at Zephyr Cove in September. Amazing! Emerald Bay is beautiful, you can take one of the paddle boats on a dinner tour there, or just around the lake (with or without dinner, they even have a dancing trip!). You can ride horses up the mountain trails in Zephry Cove...Lake Tahoe is just amazing! We can't wait to go back! This is all in "South Shore", "North Shore" is beautiful, too....we just always have gone to the south shore. Harvey's and Harrah's are good casino hotels to stay at. There is a lot of new stuff since the last time we were there, too!
Wherever you decide, I hope you have a fabulous time!! Congrats on the 10 years!
S.