A few of my favorite spots are:
Amari's on 6A in Sandwich; amazing italian food; dare I say better than the north end?! I recommend any picatta, or Parmesan dish, bruschetta, and beet salad.
Roadhouse Cafe on Main St in Hyannis has a great menu selection.
BeechTree on Main St in Hyannis has great mexican cuisine, they make guacamole tableside, and their marinated chicken wings are to die for.