It might not be loaded with the most advanced technology but the Cookshack Amerique can be load with food, programmed to smoke it to the desired temperature and then hold it there until you are ready for it. Cookshack has been making electric smokers longer than anyone and this is their best residential unit. The construction quality is excellent and with a 50 pound capacity, it is more than enough for most anyone. While more expensive than most units, this is truly the best electric smoker on the market.
The Old Smokey has also been around for a long time. This is the simplest, smallest and least expensive electric smoker on this list. It can generally be found for under $150USD. Basically, this is a smoker in a can. Everything is loaded through the top, the lid seals the chamber and it is simply turned on and left to run. You will have to check on foods and the smoke production can be a little light, but for the price it is hard to beat.