herpstats: http://spyderrobotics.com/
Helix: http://www.helixcontrols.com/DBS1000.htm
Both are excellent, the button issue with Helixs is you when you want to change the set temperature you have to go up until it reaches the maximum temperature, then it cycles back to its lowest temperature.
I use herpstats exclusively, they hold temperatures perfectly, they are the best $ for $