I love when small, compact rooms are used to the best of their functional ability. Why not take advantage of that unused space under the stairs and turn it into an extension of your kitchen? A refrigerator, wall oven, beverage center and storage cabinets take up that sloped, hard-to-fill area and don't take up additional floor space. The only thing missing in my opinion is an island. With all of that floor space, why not add even more storage or seating for your guests?