Network websites such as TBS and CW, and independent sites such as Hulu, usually offer full episodes of current television shows a few days after they come out, with content rotating weekly or biweekly.
Hulu features shows from many networks all in one place, though popular networks like HBO are not included. A subscription to Hulu Plus is required to see new episodes of popular shows. Free users usually get to see the episode a couple of days to a week after it airs. Typically, only three to five episodes of a show are available at a time, though some older shows are viewable in their entirety.