While I still enjoy a good French Vanilla Frappé at Starbucks, I have to say that Commonwealth has upped my standards of a coffee place in Fond du Lac. My favorite drink is the Caramel Macciato. It is sooooo good. The overall atmosphere is hard to beat in this small city and I can tell that the young staff is trying their best.
It does take a little longer to get your coffee (but it is AWESOME when you get it), and one time my friend's was not that hot once (turns out their coffee maker was not working well that day). He just brought it up to the counter and she gladly warmed it up again and apologized for the inconvenience. That was the only maybe negative experience I've had personally.
They also serve awsome muffins, ice cream, shakes, teas, and breakfast sandwiches. If you are around downtown FDL, make a coffee stop here. Price is a little cheaper than Starbucks, but not much. It is definitely a better experience than Starbucks tho.
The best part of Commonwealth is the fact they give back a percentage of their profits back to the community in the form of donations to various organizations. I would rather put my money somewhere where I know it will be used to help others in my community - and get good coffee at the same time!