Business dining in Madison is an art in itself.  Do your clients like seafood, steak, Americana, etc.  Depending on the type of dinner there are a number of great options in the Madison area. 

 Downtown

L'etoile (a James Beard winner) is a favorite reservations are needed in advance.  The dining room overlooks the capital square, and the food is French cuisine with American ingredients; often local meats, cheeses, and vegetabls all organic.  The food is quite good, and quite pricey.

Harvest is a local favorite too with local and organic foods being stressed here.  A bit cheaper than L'etoile, and featuring a more rustic but none the less sophisticated menu.  Again, reservations are required.

West Side / Middleton

Vin Santo -- is by far my favorite Italian resteraunt in town -- featuring HUGE portions, and excellent home made pasta dishes.  The ambiance is eclectic, and the service is fast and professional.  The owners are from Europe having worked on the Orient Express.  The dessert of bread pudding with a grappa sauce is fantastic.  A real treat is the saliccica rosa; quite spicy too.

Casabianca -- is a cheaper option and the food is more home cooking, but it has nice bright tables, and can accomodate larger groups it is off the Sauk exit heading towards Middleton.

Biaggi's -- this chain resteraunt is fun, but very homogenized in taste, but the service is good, and the free bread is always refilled. Plus they have free wireless for meetings.  The food is decent, and it won't break an expense account.