My local, been going for a year or so now. They serve Hasbean coffee and are enthusiastic about their food as well.
Won a local award for best new business and are well worth a visit if you're in the area.
At the other end of MK in Fenny Stratford there's a nice little Italian independent called Colosseo too.
http://www.buskerscoffeeshop.co.uk/www.buskerscoffeeshop.co.uk/Welcome.html