The 1st is Arabica, located at the bottom of Free Street. Lots of sun and wifi, wood and brick and larger than it's previous spot just up the block. It's always busy whenever I've stopped by.
The Bard is the newest challenger, located next to Tommy's Park and across from the sTARbucks, in the Old Port. They roast their own beans and it has a nice feel with again plenty of sun and wifi. It has nice large cups that look lovely when filled with Capuchino. I've been in here three times lately to meet someone and you can do business at either the tables the large couches or the bar.
The Hilltop has more of a neighborhood feel to it due to it's location on Munjoy Hill next to the Rosemont Market. It's very laid back, someplace to spend the late afternoon when the sun gets around to the windows, big murals on the walls make it seem gallery like.
North Star Cafe on Congress Street, at the corner of Washington, is more of an old world "Coffee House". Spend a Sunday afternoon reading the paper, an evening listening to music or poetry. The menu has much more then just pastry and coffee. You can even get a beer and watch some Burlesque, The Dirty Dishes, played their last month to a packed house and it hosts Tango every other Monday evening.
As I said Coffee By Design has multiple Locations in Portland and it's beans can be found elsewhere in the area. Located on Congress between Park and High Street (not shown here). On India Street next to Amato's that has the most laidback feel.
I've tried the coffee at all of the above at one time or another when I'm in the area, but I usually start and end the day at home with a cup of Columbian Supremo in a drip with half & half. My wife goes for Green Mountain decaf espresso, a triple with steamed milk. The coffee in Buenos Aires last spring was very good and we'll be sampling the coffeehouses in Budapest, Prague and Paris in April. While I don't take sugar with mine, I love the small raw brown chunks served along with a lemon rind that comes on your cup of Espresso in Europe. My advice is to try them all before you vote!