It wasn't that long ago, sometime in the 1950's, when dishwashing
machines emerged as the dish cleaning staple in the kitchen of most
homes. At the time, however, variety was limited and getting dishes
clean was still a kink manufacturers had not quite worked out.
Fortunately, much has changed since then. If you're out looking for a new machine you can choose from a high end model that fully integrates into your kitchen cabinetry and has whisper quiet operation so that you don't hear it running; or choose an economical dishwasher, one without the bells and whistles, but that has the ability to clean very well.
Basically, there are several types of dishwashers; however we'll stick with the most common type, the traditional 24" built-in model that fits beneath your counter. These models are broadly manufactured. In fact, appliance manufacturers such as: Miele, Bosch, Maytag, Whirlpool, Kitchennaid, Kenmore and Jenn-Air often make several lines or 24" dishwashers to choose from.
For example, Miele has Incognito, Touchtronic and Novotronic; KitchenAid has the I Series, P Series, S Series, U Series; and Bosch has the Integra and Evolution line.
While it is useful to know something about the various lines, it is not the only approach to selection. Instead, you can determine which features are most important to you: top rack adjusts for loading flexibility, stainless steel tub, delay start time option, half load option, and so on. Of course, if you like the manufacturer, knowing that Novotronic is Miele's most affordable 24" machine, whereas Incognito is Miele's top of the line, is helpful.
What's remarkable about today's dishwashers is that most perform very well at the job of cleaning. What you're paying then, are for features and technology. Features that will cost you more: quiet running (and there are different levels of quiet!), adjustable racks, cycle options and integrated design.
To shop, consider your lifestyle and the features that you need. You can buy a dishwasher for as little as $300 or you can spend $1500; not much when you consider the cost of a kitchen remodel!
Keep in mind the dish cleaning space you need inside the dishwasher. Many machines offer a half load run cycle which can be extremely useful when you've got a smaller dirty-dish load.
Also, you will find plenty of space in many machines. Jenn-Air and Maytag offer a model with 3 racks. Keep in mind capacity. Some machines wash 10 place settings, others wash up to 14. And finally, having flexible dishwasher racks can be extremely useful, especially for dinner parties, where large size platters and dinnerware need space to get clean!