I have been using this one for a year now (hooked up to a Ranco thermostat) with great results: http://www.target.com/p/holmes-hoh30..._qi_detaillink

I couldn't tell you how much it is really impacting the electricity bills, but I know it's $40/month LESS than when I had a blower-style heater. One additional recommendation I have is to get "twin draft guards" to block the crack under the door and hold the heat in better. I got mine off Amazon, but have seen them at Hope Depot, also.