In most aged cheeses, lactose is largely absent. Most of it is carried off in the whey that is separated out during the cheesemaking process. Following removal of the whey, whatever small amount of lactose is left in the cheese is then consumed over the course of aging by active bacterial cultures and converted to the more digestible lactic acid. Therefore cheeses that are young and have a high water content such as Cottage Cheese or Ricotta will consequently have more lactose than more firm, older cheeses like Gruyère or Parmigiano-Reggiano. Yogurt is also quite digestible, since it is produced with lactic-acid producing bacteria similar to those in cheese.
Of course, lactose intolerance falls on a spectrum for many people—some people are okay with one or two glasses of milk while others feel symptoms even with hard cheeses. Where do you fall on the spectrum of intolerance?