Well if you are going to be hosting a picpost or moviepost I would recommend:
http://www.swiftco.net/
I haven't had any downtime in the last several months. Downtime can really kill your trades on a free site. Also comes with some great traffic trading software:
http://www.traffictrader.net/
Really good deals on bandwidth. College Fuck Fest hosts with them. They don't have a super pretty web page or a huge internext booth but they know what they are doing. They have a solid network with several gb/s of sustained usage. Its like a pizza joint in New York. If the outside looks crappy the pizza must be great ;)