I am organizing a smallish birthday party dinner (between 6-8 people) for a foodie friend of mine in Boston. She is 20-something but quite sophisticated and stylish in her tastes in food and in life. Problem is that the people attending will be of all different ages and incomes, so I want to go with something young and fun and festive(read: rather cheap & cheerful) while at the same time offering great food. Prefer location to be in Back Bay, Beacon Hill, or South End. Any ideas?