Sure, we could do something productive with our summer in DeKalb, such as exercising, hitting the books, tanning or – God forbid – working.

Instead, do what many of us are going to do, anyway: Spend a majority of your time in front of a computer or TV screen and catch up on last season’s TV shows.

The following are the three best shows from the previous season that are returning this fall. They are easily accessible through reputable Web sites, with episodes offered free for your streaming pleasure.

“Heroes”

Stream all of the first season’s episodes for free at www.nbc.com; download the first season for $42.99 from iTunes.

Key performance: Jack Coleman as Mr. Bennet; Zach Quinto as Sylar.

Key episodes: “Company Man,” “The Hard Part,” “Homecoming.”

“Heroes” blew the cult TV community (and TV critics) out of the water last spring and fall with multilayered plotting, well-paced story arcs and memorable characters.

One part “Lost,” two parts “X-Men” and a little bit of “Buffy the Vampire Slayer” (super-powered cheerleader, hello!), “Heroes” established a winning blend of action and real human drama, but in a science-fiction context, just like the best shows in the genre.

“Brothers & Sisters”

Watch all of the first season’s episodes for free at www.abc.com; reruns at 9 p.m. Sundays on ABC.

Key performance: Besides Sally Field as Nora Walker, Matthew Rhys’ gay sibling character Kevin Walker.

Key episodes: “An Act of Will,” “Family Portrait,” “Game Night.”

“Brothers & Sisters” was the most instantly-addictive dramody of the last season. The cast is mouth-wateringly awesome, with Calista Flockhart as Kitty Walker, Rob Lowe as her boyfriend, “Six Feet Under”‘s Rachel Griffiths as Sara Whedon, “Alias” alumni and, best of all, Kevin Rhys as the non-stereotypically gay brother.

The plots aren’t anything to write home about – between the mistress story line and the incredibly mundane hedge-fund plot, I’m surprised I’ve enjoyed this show as much as I have – but the characterizations are gold and the cast’s chemistry is riveting.

“Friday Night Lights”

Watch all of the first season’s episodes for free at www.nbc.com; download the first season for $39.99 from iTunes.

Key performance: Kyle Chandler as Coach Eric Taylor.

Key episodes: “Pilot,” “Crossing the Line.”

The most critically acclaimed TV show of the past season, “Lights” struck a nerve with viewers with its documentary-style filmmaking, its American-heartland setting and its realistic situations.

The series is based on the movie of the same name. This is the most heart-wrenching show to hit TV screens in a long time. Bring the tissues.