Rent the first 4 episodes (at Blockbuster they pack 2 episodes in 1 rental)... then.. if you like it, go out and purchase it the last 2 episodes are a wrap up, and not as "intense" but its a great series, very much recommend buying it. You'll probably only see the entire thing once, and a few of the episodes a few times, its a long sit through if you want to watch the entire series from start to finish (10 hours or so..)
Take care rip...