I picked up on Smallville from the DVD's while Season 3 was going on. I watched Season One in a week and Season 2 came out a month after that and was soon completed. I saw Season 3 via the Summer repeats. They paired two shows together each week for a couple of months. Watched 4 and 5 in "real time".
Just watched Season One of Desperate Housewives this way in six nights.