What's On: So You Think You Can Outsing an Iridescent Pterodactyl

Avatar Mania (Avatranche?) is set to infect TV tonight via So You Think You Can Dance musical performances and a sit-down interview on The Jay Leno Show. Also: The movie that inspired the top-selling soundtrack of the 2000s makes a splash on country TV. Nope, it's not Coyote Ugly 3: Time to Get Off the Bar.

So You Think You Can Dance [CBS, 8 PM]

Part two of the finale (meaning this is the actual finale) brings us performances from Adam Lambert, hip-hop dance outfit The Groovaloos, and Leona Lewis, who will make flying dinosaurs bawl with her Avatar anthem "I See You." Halfway through the jam, Nigel Lythgoe is expected to apply tribal face-paint to Mary Murphy's trembling mug.

The Jay Leno Show [NBC, 10 PM]

A big night for Jay -- Sigourney Weaver and John Mayer stop by. Weaver will discuss her Avatar character Dr. Grace Augustine, how Grace's determination compares to Ellen Ripley (Alien), and how her shoulder pads compare to Katharine Parker (Working Girl). John Mayer will attempt to break Andrew WK's record for "longest sustained about-to-sneeze face during a musical performance."

The Real World/Road Rules Challenge: The Ruins Reunion [MTV, 10 PM]

In case you need more MTV violence, this reunion will serve up a confrontation between Brad and Darrell, who engaged in a fistfight that sent both players home. I love how MTV kicks off competitors who get into fights, because they're always invited back next season. Don't worry, Brad and Darrell, you can win $15,000 in a tribal-themed sandpit next year.

O Brother, Where Art Thou? [9 PM, CMT]

Rejoin the Soggy Bottom Boys as they record the indelible "I Am a Man of Constant Sorrow" and become crossroads celebrities. Aside from being (arguably) the best Coen brothers film and featuring the best George Clooney and John Goodman performances ever, the movie's soundtrack went on to win Grammy's Album of the Year and become one of the Top 20 highest-selling discs of the decade.