possibly the Cobalt Aquatics Neo-Therm Heater. This is one of the new products on the market that was engineered to beat the killer heater issue. http://www.drsfostersmith.com/produc...m?pcatid=25144
The only drawbacks I can see are the high price and relatively short track record, but I love the idea of a built in audible high temp alarm.
The other heater pros use are the titanium submersibles with separate outside the tank temp. controller. These you don't need to unplug when you do water changes. But I have a heard reports of these cooking fish, though not a often as the "consumer" products.
i have used a number of different heaters..bought over 30 aquatops and had issues with them but only with the manufacturing process which left many of the tubes cracked..company didn't care , said to deal directly with the seller..this year i bought 24 eheim jager heaters....i like them much better even if they are a couple of bucks more..