Depending on how your kitchen is set up, a countertop dishwasher might be the best choice. Some of these models are about the size of a large microwave, and can handle 4 to 8 place settings at a time, enough for a small family if done after each meal, or enough for a single person to use maybe once or twice a week. Countertop models tend to be cheaper, and could be mistaken for a toaster oven until you show your friends how cool it actually is.
Since these units are horizontal, they also might work perfectly well in a cabinet, if you have one large enough to accommodate the unit. You'll save some countertop space, and the dishwasher will hide away when not in use. Or instead, you could put the unit on top of a storage box of some kind, and create even more counter space.
Below are some of the best portable dishwashers for sale at Amazon, with consistently positive reviews, each under $300.