One of the great risks and rewards of appearing on television is that audiences begin to strongly identify actors with a particular character. It’s great to be remembered, but that can also lead to typecasting. It will probably take some time for the cast of “Lost” to live down their iconic and memorable roles. That goes double for Michael Emerson, who was so enigmatic, manipulative, creepy and occasionally vulnerable as the sneaky Ben Linus. Look for Emerson on tonight’s “Parenthood” (9 p.m., NBC) as a character with Asperger’s syndrome who hosts a birthday party for Max.

• Now it’s not enough to merely appear on a reality-television show; you have to concoct gossip-spewing events involving other media that can be “captured” on your reality-TV show. On “Joan and Melissa Know Best” (8 p.m., WE), Melissa bristles when Joan shares a little too much information on a morning radio show. Will this TMI end up on “TMZ”? No, but gossip king Perez Hilton does show up for high tea!

Will all of this tension sunder links between mother and daughter forever? Didn’t these two see what “American Chopper” did to the Teutuls?

Before folks like Perez Hilton became merely part of a celebrity’s publicity machine, gossip columnists were figures to be courted and feared. We may never go back to the days of “Sweet Smell of Success,” but tonight’s “Real Sports with Bryant Gumbel” (9 p.m., HBO) looks at one website that has been unafraid to spill the beans on sports celebrities. Correspondent Andrea Kremer visits the offices of Deadspin.com, a news-breaking, dirt-dishing organization that declares itself to be “Without access, discretion or favor.”

In other sports-scandal news, “Real Sports” profiles disgraced BALCO steroids figure Victor Conte and pays a visit to the home of boxer and celebrity oddity Mike Tyson.

• Given the problematic, not to mention depressing, aspects of human behavior, it’s comforting to tune in the concluding night of “The 135th Westminster Kennel Club Dog Show” (7 p.m., USA). The sporting, terrier and working groups get their moment in the spotlight before the “Best in Show” title is bestowed on one particular dog.

Tonight’s other highlights

• Rachel revises her image on “Glee” (7 p.m., Fox).

• A lesson in germs and genes on “Raising Hope” (8 p.m., Fox).

• Anna calls on Ryan to deal with the Fifth Column on “V” (8 p.m., ABC).

• Chicago’s diverse immigrant population serves up some “Bizarre Food with Andrew Zimmern” (8 p.m., Travel).

• A drag queen and two gang members share a grim fate on “Detroit 1-8-7” (9 p.m., ABC).

• Lights battles homesickness as he prepares for his first bout in five years on “Lights Out” (9 p.m., FX).

• Lydia suffers suspension on “Southland” (9 p.m., TNT).

Cult choice

After Earth has been trashed, it takes a robot cleaner to rekindle a spark of humanity in the 2008 animated family adventure “WALL-E” (7 p.m., Disney).