Nick News with Linda Ellerbee: The Story of September 11, 2001 (9pm, Nickelodeon) - Kids too young to remember the attacks of September 11 discuss their questions about the event with journalist Linda Ellerbee.

Project Runway (9pm, Lifetime) - The seamsters union join forces with art students to create artwork that will inspire clothing designs. Designer Kenneth Cole is the guest judge.

Sweet Home Alabama (9pm, CMT) - Devin chooses between the last two suitors in the first season finale.

Ultimate Merger (9pm, TV One) - A military obstacle course must be tackled to win a date with Toccara.

Suits (10pm, USA) - Harvey's former mentor (Gary Cole) turns to his protege when his office comes under investigation. Meanwhile, Mike and Louis try to settle a mogul's estate in the midst of family clashes, and Jenny worries that Mike is hiding something.

Louie (10:30pm, FX) - Louie's distraught sister drops off her daughter at Grand Central Station and then gets back on the train that brought them to New York. Comedians Godfrey, Todd Barry, and Nick DiPaolo appear as themselves.

The Green Room with Paul Provenza (11pm, Showtime) - Season 2 ends with comedians Eddie Izzard, Jimmy Carr, Judah Friedlander, Chris Hardwick, and Tim Minchin.

Detroit in Overdrive (8pm, Planet Green) - All three installments tonight in a new three-part documentary series examining efforts to revitalize the city of Detroit. In the first, Kid Rock launches a beer label (Badass Beer) and fashion designer Joe Faris tries to revive the Motor City's garment district. At 9, the show looks at a start-up record label and a famous artist's installation, as well as a high school trumpet player who auditions for a music scholarship. The episode at 10 visits a former auto body plant that houses small businesses and a community of artists.

So You Think You Can Dance (8pm, Fox) - "American Idol" contestant Pia Toscano performs, and two dancers are sent home.

Ultimate Merger (9pm, TV One) - In the Season 2 opener, model Tocarra Jones looks for a mate and meets 12 suitors who try to win her over. Adrienne reviews.

Project Runway (9pm, Lifetime) - The designers must make fashion from items found in a pet store.

Suits (10pm, USA) - Mike takes on Louis' protege during a mock trial, but his conflict with Rachel could hurt his chances of winning. Meanwhile, Harvey works on a merger between two hotel chains, but his past with the opposing counsel complicates matters.

Jersey Shore (10pm, MTV) - The new season begins tonight and the bad news for Europe is that it all takes place in Italy. Watch Snooki crash into an Italian police car and get arrested. Watch Ronnie beat on The Situation. Watch me watch "Suits" at 10 p.m. instead...

Louie  (10:30pm, FX) - Louie reflects on his career failures and tries to score concert tickets for his daughter. Comics Dane Cook and Bob Saget play themselves.

Big Brother (8pm, CBS) - It's elimination night on "Big Brother" and also on "So You Think You Can Dance" (9pm, Fox).

Real Housewives of D.C. (9pm, Bravo) - It's the newest set of Bravo housewives and they've already gained notoriety. At least the Salahis have. Here's what Adrienne has to say about the premiere.

Bethenny Getting Married? (10pm, Bravo) - Now this is a Bravo show I can get behind. I even got a little weepy last week watching new dad Jason Hoppy  with his newborn baby girl. What a surprisingly great little series this turned out to be! In tonight's season finale, Alex McCord (RHoNY) throws Bethenny an official baby shower and then the Hoppy family goes away for the weekend, Nanny in tow (but wait, where's the crib?!).

Royal Pains (10pm, USA) - Hank examines Dr. Blair's son, who is reeling from his parents divorce. Evan is still posing as Paige's boyfriend, and when he goes to meet her parents, he discovers he has real feelings for her.

Boston Med (10pm, ABC) - A former firefighter has surgery to remove a cancerous tumor from his colon and waits to see if he needs chemotherapy. Also, a 4-year-old girl's life is in danger when it's discovered she suffers from a brain bleed.

Ultimate Merger (10pm, TV One) - Another season finale. Tonight, the remaining men have one last chance to impress Omarosa. Does she find love? 

Big Brother 12 (8pm, CBS) - The twelfth installment of "Big Brother" begins tonight. The  house guests are introduced and we learn that one of them is a saboteur whose sole mission is to wreak havoc in the house. So it's sort of a "Big Brother" meets "The Mole" this time around. Who will it be?

Rookie Blue (9pm, ABC) - The police department throws a "Fite Night" charity event, and Andy faces a tough decision regarding a domestic violence victim.

Boston Med (10pm, ABC) - A neurosurgeon prepares for a risky surgery removing a cancerous tumor from a man's sinus cavity. Also, a first year surgery resident attempts his first appendectomy and discusses dating prospects with a colleague.

Bethenny's Getting Married? (10pm, Bravo) - This is it: wedding day.

Ace of Cakes (10pm, Food) - Duff builds his tallest cake ever, modeled after an Egyptian pharaoh, but transporting it turns out to be a huge problem.

The Ultimate Merger (10pm, TV One) - Chef G. Garvin helps the bachelors with a cooking challenge, and ends up clashing with one of them. I'm still trying to figure out why any of these men want to date Omarosa to start with.

100 Questions (8:30pm, NBC) - Charlotte and Wayne compete to see who can be the first to have a one-night-stand. Jill and Leslie help Charlotte score a firefighter, and Mike helps Wayne with an Israeli model (wait - Wayne needs help?). I'm going to miss this little sitcom when NBC cancels it.

Rookie Blue (9pm, ABC) - If this show were a beer, it'd be called "Southland Ultra Lite." Tonight, Andy and her training officer look for an informant whose cover has been blown, while the other rookies are involved in a manhunt for a violent escaped convict.

So You Think You Can Dance (9pm, Fox) - Ne-Yo sings "Beautiful Monster" and there's a performance of "Return to Sender" from Cirque du Soleil's ELVIS.

Ultimate Merger (10pm, TV One) - The remaining men courting Omarosa (left, with Al B. Sure) face a debate challenge, with comedian George Wallace as judge. TV One is channel 330 on Time Warner Cable.

Boston Med (10pm, Fox) - In the second installment of this compelling docu-series, a soldier is reunited with his family for the first time since the birth of his son, who is born with a heart defect requiring surgery. Also, a nurse copes with unruly behavior in the ER.

Bethenny Getting Married? (10pm, Bravo) - The wedding draws closer and Bethenny is still extremely stressed out. Jason doesn't want to help with the planning, Alex McCord from "Real Housewives" throws Bethenny a shower, and Bethenny attends her rehearsal brunch.