For the average buyer, I suggest buying a five-quart air fryer. The basket is large enough to not be crammed when cooking for your family, but won't take up too much space on the counter.
For two-person households, between two and four quarts of capacity will serve your day-to-day air frying needs. However, if you want to cook for more than two people or you plan on cooking two elements of your meal at once, some of the top dual-drawer air fryers offer up to nine quarts of cooking space.