I use a Brinkmann Smoke n' Grill
it's okay. The cheap ones have issues with keeping temperatures steady. I've made a bunch of modifications to mine and got it finally stable for the first time last month (owned it for 3 years now).
And if you are looking at a charcoal smoker, consider how easy it is to get to the charcoal/water pans. The cheap ones are sometimes a real pain. Also, check to make sure there is enough air vents for temp control and a decent thermometer. The thermometer that came with mine just simply said "warm, ideal, hot". What the hell temperature is 'ideal'?
An electric smoker would be nice...but consider the weather. Electricity and rain don't mix (and it always seems to rain/snow when I smoke)
Gas is also handy with keeping a steady temperature, but of course you have to worry about the fuel going out.
If you want a simple smoker that works great, just use a large charcoal grill. BBQing is all about low-and-slow with indirect heat. Coals on one side of the grill, meat on the other. Then just add your chips/chunks. Check out how these guys do it:
http://www.bbqpitboys.com/
Awesome recipes on that site and all with a simple grill.