Barefoot Coffee does a darker blend called Haiku that is quite delicious and not over-roasted. This would be my first suggestion, and they are a Third Wave roaster. Also try Mr. Espresso's Espresso Toscano. It's similar to the Haiku and a touch mellower. I also like the Mr. Espresso Golden Gate Espresso and Espresso di Carlo. The latter two are lighter and more complex than the Toscano but aren't intensely acidic or fruity. If some of those characteristics show up try finer grind, lower dose, higher temperature. They are somewhat like Counter Culture's Espresso Rustico. Mr. Espresso has made a business of supplying local restaurants (like Il Fornaio) and their Espresso Toscano is very forgiving. Like typical Italian espresso sometimes their blends benefit from a touch of sugar and they're actually roasted for that, but I like them without. You can try the Espresso Toscano at The Coffee Bar on Montgomery, which is owned by them. They brew it with care on top grade gear. Another local favorite is the espresso blend at Cafe Trieste in North Beach, though they're not "Third Wave" either. Connoisseur Coffee in Redwood City is distributed at groceries and has particularly gentle roasts into second crack and is similar to Cafe Trieste. If you ever have a craving for Peet's but want something much more subtle you might find it worthwhile.
What I WOULD do for a good cup of coffee!