Advice for recycling old phones

Anyone in the USA have advice on where to recycle your old phone. They have ecoATM machines here but that would require a bus trip. Has anyone used some mail-in service? I know to do a factory reset on the phone before I recycle it.

Let me know how it went with you.

Edit - the thought just occurred to me to try Best Buy.

I heard that gazelle was a good online place to sell your phone.