What to Watch: The TVLine-Up for Thursday

On TV this Thursday: Finales galore! The Vampire Diaries, The Big Bang Theory, The Secret Circle, The Office and Parks and Recreation all end their seasons, and more. In addition to TVLine’s original features (linked within), here are eight programs to keep on your radar.

PREVIEW | Vampire Diaries Star Previews ‘Wow’ Finale and New Threat to Tyler/Caroline

8 pm The Big Bang Theory (CBS) | Season 5 finale: The gang rushes to put on a wedding when Howard and Bernadette decide they want to be married before his NASA launch. (Get scoop!)

8 pm Community (NBC) | Abed is the only one to realize that Dean Pelton is an impostor, but his conspiracy theory lands him in front of a therapist (The Daily Show‘s John Hodgman). The alternative? Jail, naturally.

8:30 pm 30 Rock (NBC) | Avery finally returns, but Jack is immediately suspicious of her indifference about Diana; Liz’s breadwinner status excites her, while Criss’ hot dog shiller status disapproves.

PREVIEW | Secret Circle Boss on Finale’s ‘Epic’ Body Count, Unlikely Romance and Blackwell’s Endgame

9 pm Grey’s Anatomy (ABC) | As the residents contemplate their next moves, Mark weighs his love for Lexie against a guaranteed future with Julia; Arizona encourages her tumor-ridden childhood friend to have surgery; a couple on their third honeymoon (24‘s Mary Lynn Rajskub and Lost‘s Patrick Fischler) arrives at Seattle Grace with mysterious symptoms. (Hey, did you hear who’s back next season?)

9 pm Person of Interest (CBS) | The latest POI’s curiosity could spell his doom as he gets pulled into a dark government conspiracy – one with which Finch is all too familiar. Justified‘s Jacob Pitts guest-stars.

9 pm The Office (NBC) | Season 8 finale: Andy returns to Dunder Mifflin as a janitor, harboring a secret plan; Dwight goes to great lengths to steal a DNA sample from Angela’s baby in order to prove his paternity. (Watch an exclusive video of Jim’s last prank of the season!)

9:30 pm Parks and Recreation (NBC) | Season 4 finale: Leslie and Bobby Newport are neck-and-neck in the Pawnee election, and all the Parks Department can do is wait (and drink, as teased by stars Retta and Aubrey Plaza in Spoiler Alert!)

PREVIEW | Scandal‘s Tony Goldwyn: Flashback Episode Shows Soulmates In an Impossible Situation

PREVIEW | Exclusive Awake Video: Has Britten Found ‘The Little Guy’? Or Is He [Spoiler]ing?

10 pm The Mentalist (CBS) | On the eighth anniversary of his wife and daughter’s death, Jane receives a message from Red John, causing him to lose focus on his current case and put the investigation — and his career — in jeopardy. Twin Peaks‘ Ray Wise guest-stars.

Which of the above is must-see for you? Also, hit Comments to offer your own tune-in suggestions.