Particularly noteworthy items include the (city of) Santa Clara and San Jose mayoral races, both of which involve trusted progressives (Patricia Mahan and Cindy Chavez), running against conservative Dems who have relied on major Republican donors to fund and organize their candidacies (John McLemore and Chuck Reed), like Lieberman in CT.
Also, I'll note that I disagree with San Francisco on Bevan Dufty. I've met his opponent, Alix Rosenthal and liked her. SFBrianCL, of Calitics, wrote an endorsement for her. She wasn't eligible for the Democratic party's endorsement because she's a Green. She does, of course, have the endorsement of current Green councilman Ross Mirkarimi, whom I've chatted with at a few events. I found both of them more willing than average to discuss, and think about, technical issues like voting systems, and they're by no means far-out fringe candidates who don't appreciate the pragmatic aspects of politics -- both have even done campaigning for Democratic candidates. In fact, I originally met both of them at Dem-sponsored fundraiser events.