It's hard to say without knowing your likes and interests. Do you want to keep costs minimal and see SJ or do you want to make a trip out of the MR? You can actually get a decent hotel and spend a night up in Napa/Sonoma, then check out and go to your game, and stay near SJC before your flight. Or go south and hang out in Monterey/Carmel for a night.
If you've never been, check out Santana Row - the most "exciting" shopping/dining area advertised in SJ. Or outlet shopping at the Great Mall.
There are plenty of tickets on Stubhub.