I am currently using a hydrofarm on my cricket breeding tubs. It isn't very accurate, but it is better than nothing.

A step up would be the Ranco Thermostat. These are far more accurate but still not nearly as accurate as the Herpstat

Ranco: http://www.reptilebasics.com/ranco-etc-111000-pre-wired

I use Herpstats exclusively for my reptiles. They aren't cheap but they are worth it.