Top 3 sites to sell my iPhone 5S on?

Need to sell my phone pretty quickly and don't want to wait too long to get paid. What are your picks for selling online?

Www.upgradeswap.com
www.swappa.com
www.usell.com
AND
http://www.gazelle.com/

Be careful. If you're dumping it right before the bill cuts off, the carrier will blacklist the serial number and it's value to anyone will be just parts or as an iPod. Hardly any bad serial numbers ever get reactivated in the US. These sites will ask those questions and run the serial to see if it's lost/stolen already.
Craigslist it and move on with life if that's the case. Best luck.

Www.upgradeswap.com (they pay same day)
www.swappa.com
www.usell.com

If you need the money right away I would recommend using upgradeswap.com since someone mentioned that they pay you the same day.