Decaf coffee generally has from 5-15mg per serving.
Interesting note: The darker the roast, the stronger the taste, but the less caffeine content.
One cup of a nice medium / light roast coffee has about 150mg caffeine. However, one shot of espresso has only one-third to one-half that.
And for the record, Starbucks brewed coffee tastes like monkey poo. Peet's / Coffee Bean / Diedrich's 0wnz.
I'm a total coffee freak. I generally get a triple or quad mocha at Starbucks when I go there, or a large brewed coffee (20 oz) anywhere else. However, if I'm at a diner that gives you an entire carafe, I'll drink 8-12 cups easily. I only get mildly wired after that. Hm.