In my experience, the most flavorful mushroom pasta dishes are the ones that utilize multiple types of mushrooms. Some varieties have a more meaty texture and mild flavor, while others are lighter and possess a more savory flavor.  White mushrooms and portobello mushrooms tend to be cheaper but lack in flavor. If you use those, I recommend pairing them with a more flavorful variety like chanterelle, oyster, porcini, or shiitake mushrooms.