What to Watch Tonight: Community's Season 6 Premiere, the Debuts of iZombie and One Big Happy, and the Series Finale of Perception

What to watch on Tuesday, March 17...

SEASON 6 PREMIERE, 12:01am, Yahoo
Community
By sheer force of the internet's will, the Greendale Human Beings—down one Yvette Nicole Brown but up a Paget Brewster and a Keith David—return for a sixth season (albeit on a platform that's off the beaten TV path even by 2015 standards). The first two installments of the 13-episode season drop today, with new episodes weekly on Tuesdays.

8pm, The CW
The Flash
What's this? That malevolent meteorological manipulator the Weather Wizard blowing into Central City—and aiming his atmospheric assault at Joe? Can the Scarlet Speedster stymie the revenge-minded Rogue, or will foul play be in the fearsome forecast? And what will Cisco learn of the Reverse Flash? Tune in to "Out of Time" to find out—same Flash-time, same Flash-channel!

8pm, ABC Family
Pretty Little Liars
A surprise witness spells bad news for Alison's case as her trial nears its conclusion in "I'm a Good Girl, I Am." Can Aria, Emily, and Spencer find any evidence to tilt the balance in their friend's favor? Considering they've been coming up with bupkis for, what, three or four straight weeks now, I don't like their chances.

SERIES PREMIERE, 9pm, The CW
iZombie
A former medical resident turned undead gumshoe helps the Seattle police solve crimes in the latest series from Veronica Mars creator Rob Thomas, adapted from the Vertigo comic book. The opener finds newly quasi-deceased Liv discovering that human brains aren't just yummy and nutritious—they also let her tap into their former owners' memories.

SEASON 5 FINALE, 9pm, TNT
Rizzoli & Isles
In "Family Matters," a murder investigation gets complicated when it turns out that the victim may have been living a double life. How in the heck are people on TV always living double lives? Raise your hand if you barely have the energy to handle just the one life most days. C'mon, don't be embarrassed, no one can see you, you're literally sitting alone looking at a screen.

9pm, ABC
Marvel's Agents of S.H.I.E.L.D.
"One of Us" finds Cal assembling a cadre of supervillains to exact his revenge on Coulson and S.H.I.E.L.D. Why, he's lined up all the heavy hitters! Doctor Doom!, Norman Osborn!, Magneto!... um... Paste-Pot Pete, maybe?

SEASON 2 PREMIERE, 9pm, NBC
Undateable
Justin's attempt to have a one-night stand goes pear-shaped in "A Japanese Businessman Walks Into a Bar." Elsewhere, the bar's newest drink-slinger struggles with the job's learning curve, and Leslie suspects that a gym is exploiting her image in an unseemly fashion.

SERIES PREMIERE, 9:30pm, NBC
One Big Happy
Elisha Cuthbert stars in this family sitcom from producer Ellen DeGeneres, following two platonic friends, Lizzy and Luke, who decide to a) make and b) raise a baby. Throwing a wrench in their plan: Luke's whirlwind romance with and marriage to a woman who rubs Lizzy the wrong way.

9:30pm, Fox
The Mindy Project
Concerned about her body image as her pregnancy begins to announce itself, Mindy consults an up-and-coming personal stylist (Laverne Cox). Meanwhile in "What to Expect When You're Expanding," Jeremy cautiously re-enters the dating world, where he bumps into Morgan's girlfriend Jessica.

SERIES FINALE, 10pm, TNT
Perception
"Run" wraps the series with Moretti's wedding day, and only one thing is missing: the bride. Can Pierce and Donnie save her from the clutches of Pierce's old enemy? And can the combination of an open bar and Cousin Gladys's unconventional spin on the Great American Songbook keep the guests occupied while the rescue mission is underway?

10pm, BET
Being Mary Jane
"Let's Go Crazy" reveals why Mary Jane decided to get cozy with David, and finds a Talk Back segment inspiring her to fix her fractured relationships.

10pm, FX
Justified
Ava remains torn between Boyd and Raylan in "Burned," but of course Option C—skip town altogether and open the quaintest little haberdashery in Paducah—is still on the table. Elsewhere, Markham's designs on Harlan are flummoxed.

10pm, USA
Sirens
In "Charbroiled," a family barbecue is the site of escalating tensions, including a drunken donnybrook between Cubs fans and White Sox fans that reminds us all that spring is nearly upon us at last.

10pm, NBC
Chicago Fire
"Forgiving, Relentless, Unconditional" is tonight's best episode title that would also make a nifty summary line for a dating profile. Also good for impressing potential paramours: Saving a toddler from a structure fire, as Hermann does, before investigating the shady circumstances surrounding the blaze. Elsewhere, Severide tries to reconnect with childhood chums while Cruz and Brett reach a crossroads in their relationship.

10:30pm, Comedy Central
Kroll Show
"The Time of My Life" follows Dr. Armond to Europe in search of his wife's killer, and follows C-Czar and Bob Ducca to the PubLIZity offices, where they pitch their new invention.

10:30pm, TBS
Cougar Town
The Cul-de-Sac Crew celebrates "Climb That Hill," their 100th episode, by taking on new personal challenges. Jules tackles reading a book, Grayson tries to be more attentive when his friends are speaking, and Andy works on quitting a bad habit.

LATE-NITE:
– Zachary Quinto, Kristen Schaal, and OK Go on Conan, 11pm, TBS
– Amanda Seyfried on The Daily Show with Jon Stewart, 11pm, Comedy Central
– TBD on The Nightly Show with Larry Wilmore, 11:30pm, Comedy Central
– Jennifer Garner, Eugene Levy, and Modest Mouse on The Tonight Show Starring Jimmy Fallon, 11:35pm, NBC
– Will Ferrell and Glen Hansard on Late Show with David Letterman, 11:35pm, CBS
– From South by Southwest, Julia Louis-Dreyfus, Robert Rodriguez, and Spoon on Jimmy Kimmel Live, 11:35pm, ABC
– Shailene Woodley, Jason Biggs, and Alex Gibney on Late Night with Seth Meyers, 12:35am, NBC

WHAT ARE YOU WATCHING TONIGHT?