cycling shoes with exposed cleats such as look, time, spd sl etc are the best shoe for actually cycling in, as they allow a better transfer of power from foot to pedal. you can get cleats with 9° of float which will stop you getting sore knees. the drawback to these shoes is that they are awkward to walk in (and it wears the cleats out). they are exellent for any road riding where you don't spend too much time off the bike, and are the choice of any racing cyclist.
cycling shoes with recessed cleats such as shimano spd are a lot easier to walk in, and still provide a better transfer of power and are also safer than traditional toeclips. they are excellent for touring and also mountain biking. the disadvantage is that they are less efficient in power transfer than exposed cleat systems.
in both instances, the cleats are specific to the pedal (and are usually supplied with the pedals, not the shoes). not all shoes take all cleat types, so check this carefully when buying pedals and shoes.
my preference: look. but there are better cyclists than me who will happily ride the saturday club run with spds on account of the café stop. horses for courses.
hope this answers your question.