Prison break fan here! Beware of the sites with Zango, it will mess up your computer.

go to http://www.hulu.com. they have a WIDE selection of clips, episodes, and movies absolutely FREE! no ads, no pay, no wait, and u can watch ANYTHING u like on that website. in fact, every friday like today is hulu night, i watch stuff on hulu. trust me, its much betr than fancast.

http://www.GRAB0lD.com will let you stream them in good quality if your connection can handle at least 250 KB/sec. They have every episode, it is where I watch Prison Break.
Hope that helps.

Havenvideo.com
Loads of full length movies, TV Shows, Music Videos etc updated daily, the best site on the net and all free with no zango or pop ups, enjoy http://www.havenvideo.com/

try surf the channelhttp://www.surfthechannel.com/show/164.h…
i am after watching one

why not to try youtube? Still powered by zango ?
And I always consider that watching dvd will be much more convenient, also could collect some favourite ones.

hulu.com or fox.com/prisonbreak.
They all have ads, those are unavoidable.

try episode downloader ,it will help you .http://www.downloadepisodes.net/download…
^_^

http://www.surfthechannel.com/show/164.h...

Fancast.com
they have a bunchhh of shows and movies you can watch for free =]

http://www.globaltv.com
it has all the episodes of this season.

Try Sidereel.com. They have many TV show that you can watch for free.