Good, inexpensive, basic smart phone?

My parents are to the stage where they want to get smartphones, and are looking at tmoble since they have the "no contract" thing and will let you use your own phone. I know logan talked about a $100 phone in a video not too too long ago so that may be a place to start.  Really though I don't really know much about smart phones beyond the nexus or galaxy though, so I'm in need of a bit of help if anyone can provide some.

Those $100 phones are meant for developing or third-world countries. They are hardly usable. I would look into the Moto G, around $180 unlocked I think. Much better phone.

backing the moto G here, i have mine for a few months now, and never looked back to my old phone. they are worth every single dollar, the battery life is pretty amazing as well, mine hasnt been charged in 6 days, and the battery is half way.

If the moto G is too expensive I heard good things about the moto E.

Thanks, I'll look in to that, they really don't have more than $100 to spend on a phone a piece. 

Older phone is also be given a chance. Galaxy nexus or the Nexus 4 are both great phones.