Frigidaire, owned by Electrolux, is likely the most popular 18 inch dishwasher on the market. This is primarily due to the numerous high end features that are available for the price of a mid-range dishwasher.
Frigidaire has most accurately mimicked the features of their high end full size professional series dishwashers in a compact size. Offering a direct feed upper wash system, stainless steel tub, nylon coated racks with tines in the upper rack and a heated convection drying system.
The only thing lacking in this well designed 18 inch dishwasher is a built in hard food disposal and upper rack only wash. But in a compact dishwasher these are features that are not needed to the degree they would be in a full size dishwasher.
We like this dishwasher so much we've located as many potential sellers as possible. Below on the left are 18 inch dishwashers you may purchase direct from several online retailers. Units available through Amazon are in the middle and on the right are eBay auctions that feature this Frigidaire compact dishwasher.