Almost everyone knows about GPT, and similar websites but there are few sites that are different that aren't as popular or well known....
Humanatic - You get paid to listen to calls and answer a question about how quickly the person was able to talk to a qualified employee. It's easy but somewhat low paying, however they do offer bonuses.
Slice The Pie - You get paid to listen to music and review it. It is one of the higher paying websites available. It can be fun but also annoying.
SnapWire - If you are good at photography then you may want to check it out.
ShutterStock - Supposedly you are supposed to be able to earn from photos if they are accepted.
Ideas:
Sell on Etsy
Sell old college books on Amazon Trade In
If I come across anymore unique ways to earn at home, I will list them here.