Prison Break is definitely one of my all-time favourites, season 1 is the best one.
Breaking bad was fantastic, as mentioned above the first season can be a bit slow, especially the first episode, but it gets better (trust me). You will find yourself watching about 2-3 episodes a day!
Game of Thrones - Now at the beginning, I never was into the sort of fantasy/medieval stuff and thought I wouldn't like it. But boy, did I get into it! Has to be the best series I've watched to date, up there with the other two! Bring on Season 5!
Better Call Saul - Good series so far, you don't have to watch breaking bad first to watch this, but it's probably nicer if you did, because you go into the series with a certain predisposition of the main character, which then changes as you watch it, which sort of makes it better.
House of Cards - Started watching this (only finished episode 1 of season 1) but it's interesting so far.
Been watching Gotham too, but stopped when I started game of thrones lol Will resume shortly.
Still got loads more to see, like the Blacklist and a few others!