Rewind Guide: How to Catch Up on Shows You've Missed
Returns: This fall for Season 6
What You Can Skip: Seasons 3 and 4
You'll miss the cherished Jenny Humphrey episodes, but since the writers basically forgot about her, Eric van der Woodsen, and Vanessa Abrams, it's OK to skip the college years. You could probably jump into the sixth season without being too confused (this is a CW show, after all), but given that it's the final 10 or so episodes, you never know what random characters or story lines the writers will bring back from the dead.