If you like Pho and Taco's you definitely find plenty in San Jose! if you like donuts, try Phsyco Donuts if ur in SJ! also you can check out the Winchester House too if you're into the history of that place.
Sunnyvale doesn't have much, but if you go to Mountain view which is a county over, you can check out the Tech Museum and also the Google Campus there. Facebook has a campus in Palo Alto too if you are into the social network stuff.
if you want to get fancy and take your wife out to a nice fancy dinner, Santana Row is a nice place to spend a nice evening.
if ur not into that, I recommend San Pedro square in downtown SJ, a lot of open bars, food courts and live bands will play if you're not into the night club scene and just want to eat, drink and ppl watch lol. FYI it gets really packed when the Sharks play as everyone will meet there before going to the game to get loaded, it's cheaper, lol.
if you're into the beach life, I recommend Santa Cruz, Capitola beach, and Monterey Bay.