I liked all the seasons, especially season 3. Where they got into another an unzanitized prison in a latin country across the border. The conditions in that prison were horrible with no rules and the inmates were worse where you had to really fend for yourself.
It's interesting to note that Robber Knepper, the guy that played the sadistic killer, Theodore bagwell aka T-Bag will reprise his role in an A&E show called "Breakout Kings" about US Marshalls on the hunt for fugitives. Knepper said he will only do it if his character won't die.
Everytime I see T-Bag on screen, I sometimes think even the actor is a stone cold killer.