8 p.m., ABCJason Mesnick weds Molly Malaney, who he actually rejected last year in the final rose ceremony. Their wedding features performances from Gavin DeGraw and former American Idol contestant Jason Castro. Plus, we'll get to see footage from the bachelor and bachelorette parties. Classy!
8 p.m., CBSCobie Smulders), who is apparently still miffed about her breakup with Barney (Neil Patrick Harris), gets a self-help book author (guest star Jennifer Lopez) to help her get back at him.
8 p.m., FOXHugh Laurie) and his team treat a mysteriously bruised and bleeding blogger (nice to see ya, guest star Laura Prepon!), who proceeds to piss off the doctors when she blogs about her experiences in the hospital.
9 p.m., CWChace Crawford) and Serena (Blake Lively) get more than friendly, while Dan (Penn Badgley) and Vanessa (Jessica Szohr) try to stay just friends after Dan's word-vomity profession of love. Glad you're all back, Upper East Siders.
10 p.m., ABCNathan Fillion) and Beckett (Stana Katic) investigate the murder of a woman found in bondage cuffs and covered in caramel sauce. The title of the episode? "The Mistress Always Spanks Twice." I wonder how many times Castle will say the word "kinky" in this episode.
10 p.m., NGC
Aftermath: World Without OilOn a less amusing note, this program examines what the world would (will?) be like if (when?) the oil supply ran out.
Also on the airwaves...
Chuck, 8 p.m., NBC
Life Unexpected, 8 p.m., CW
The Secret Life of the American Teenager, 8 p.m., ABC Family
Rules of Engagement, 8:30 p.m., CBS
Two and a Half Men, 9 p.m., CBS
24, 9 p.m., FOX
Trauma, 9 p.m., NBC
Make It or Break It, Season 1 finale, 9 p.m., ABC Family
The Big Bang Theory, 9:30 p.m., CBS
CSI: Miami, 10 p.m., CBS
Law and Order, 10 p.m., NBC
Greek, 10 p.m., ABC Family
Kell on Earth, 10 p.m., BRAVO
Damages, 10 p.m., FX
Secret Diary of a Call Girl, 10 p.m., SHO
Anthony Bourdain: No Reservations, 10 p.m., TRAVEL
NHL Hockey: Stars v. Capitals
What are you watching tonight?
Follow TV.com writer Stefanie Lee on Twitter: @StefAtTVDotCom