Since the OP was asking about electric smokers, I have split the Chargriller posts off into their own thread in the Grills & Smokers Forum titled Chargriller.
Chile, the Brinkman runs about $100 and I have heard good and bad about them. The good is that it does a good job and if you have a charcoal version you can get a conversion unit (base plate and heating element) for about $35-$40. The bad is that the heating element and/or electric cord seems to burn out rather quickly - about once a year if used on a frequent regular basis according to what I have read from the people who have them.
I have a friend that has a Masterbuilt Electric Smoker
that he picked up at Cabela's a few years ago that he uses quite frequently, even during the winter, and hasn't had any problems with it - but it was $200. Cabela's has a couple of smaller and cheaper smokers Smokehouse Big Chief ($150) and the Mini-Chief ($100) that look like they might be worth looking at.
Of course - you could always make your own out of a cardboard box like Alton Brown did when he smoked salmon in: