Aqueon is good for heaters! Plus, they have a lifetime warranty. Got mine at Petsmart. They always go on sale, so they aren't too expensive. I have a 100 watt for my 10 gallon because it sometimes gets cold in my room and I don't want the heater to have to stress itself to heat.
I have trouble with aqueon keeping the temp steady. I'm not a fan... I have tried many in many different tanks(currently running 10 tanks 2.5-75g) Fluval and ehiem jager are my favs. For 10g I always go with 50watt of either brand. You can find at petco, petsmart or better yet try amazon if you can order online.