I haven't had any bad experiences with any particular brand of heater. I've been using Finnex Titanium heaters without any trouble. But, I have been running a controller on my system as backup to make sure the aquarium never overheats (shutting off the outlet) or fails to heat (by sending me a message). I've never had either of those two cases happen, but it's nice to have the peace of mind.
My only recommendation is stay away from glass heaters. They're a nightmare waiting to happen.
This is a little late for a response, because you probably already went shopping today. What did you get?