5 shows we'd quit if the best characters left By TODAY staff Peter Dinklage as Tyrion Lannister on "Game of Thrones," Maggie Smith as the Dowager Countess on "Downton Abbey," and Jim Parsons as Sheldon Cooper on "Big Bang Theory." Ensemble casts on television often give their shows a great chemistry that can't be beat. But when one person makes an exit, it can sometimes change the flavor too much, throwing off the delicate balance and leaving fans wondering if it's time to change the channel. (Remember when David Duchovny left "X Files"? Or when George Clooney bailed on "ER"? How Steve Carell quit "The Office"?) Siobhan Finneran's announcement last week that she was leaving "Downton Abbey" left fans of the period drama torn. Good riddance to nasty maid O'Brien, some declared, while others wondered who -- if anyone -- could stir the pot of trouble she so expertly handled. That got us thinking: Which shows would we quit if certain characters left? Here's what we came up with: The Dowager Countess, 'Downton Abbey' Everyone focuses on the Dowager Countess" many witty quips on "Downton Abbey." And for good reason -- they're great. "Oh my dear, you flatter me, which is just as it should be." But they're only part of why the Dowager IS "Downton." Even though Maggie Smith is 78, her physical acting can either break your heart or break you up in giggles. Who can forget her battle with Matthew Crawley's unexpected swivel chair? As with everything, she blames the Americans. And though everyone keened over Lady Sybil's death, it was the Dowager who delivered the most touching tribute. "We've seen some troubles, you and I," she tells Carson. Nothing worse than this. And as she walks forward, her grief nearly knocks her down, like a swell in the ocean. For just a minute, she has to grab the wall to steady herself before walking forward alone, a black-clad ship that's been battered, but cannot allow itself to sink. -- Gael Fashingbauer Cooper Tyrion Lannister, 'Game of Thrones' There's no shortage of great characters on HBO's "Game of Thrones." Some have been with the show since the beginning, such as dragon matriarch Dany. Some of the best ones are later additions, like the Onion Knight himself, Davos Seaworth. And some of the greats are already long gone -- RIP, Ned Stark. But there's really only one character the show could never do without. Battles would be less cunning and trips to the brothels far less funny without the true lion of the Lannisters, Tyrion. He dishes more dry one-liners than "Downton's" Dowager ("I'm a monster, as well as a dwarf -- you should charge me double") with a decidedly deadlier streak ("Those are brave men knocking at our door. Let's go kill them!"). -- Ree Hines Sheldon Cooper, 'The Big Bang Theory' Yes, Penny, Leonard, Howard, Bernadette, Raj and Amy Farrah Fowler all have their bright moments on the show (and quite a few of them!), but without their brilliant, egotistical and socially incompetent pal Sheldon, there would be no one around to give them the hilarious situations they always find themselves in. Sure, one episode had Sheldon discovering that his friends could survive without him in their social group -- and quite well, at that -- but whether the comedy could do the same is another question. Yes, some shows have continued by recasting major roles (Becky on "Roseanne," Darrin on "Bewitched," for example). But could another actor truly capture the essence of Sheldon as Jim Parsons does? As the theoretical physicist might say, "That is highly illogical." -- Anna Chan Roger Sterling, 'Mad Men' I've always suspected that Roger Sterling could go the Lane route and off himself at a moment's notice. After all, he's a double divorcé who wiles away his worries with drinks, unfulfilling sexual dalliances and Pete-bashing witticisms. Who doesn't love to hate Pete, though? But that was before Joan and Roger's little accident. It's given Roger something to live for and the once-self-centered man, a man who left his first wife because she was getting too old, may be entering a state of reform and taking a step back from the proverbial rooftop edge. At least I hope so. I couldn't imagine "Mad Men" without such a politically incorrect hedonist in the mix. A man who excuses his infidelity by saying, "We've all parked in the wrong garage." A man who looks at a journalist with a peg leg and says, "They're so cheap they can't even afford a whole reporter." Roger's a man who says exactly what he wants to say when he wants to say it. Rude? Hilarious and charming? Even more so. -- Cody Delistraty Lafayette, 'True Blood' Bon Temps is crawling with interesting characters, be they living, dead or somewhere in between. Of course, most of the action in the creepy bayou backwoods revolves around "True Blood's' leading lady, Sookie Stackhouse -- the fellas in town certainly can't get enough of her. But while losing Sookie might be a deal breaker for Bill, Eric or Alcide, that doesn't mean she's the important character as far as those of us on the other side of the screen are concerned. "True Blood" would lose most of its heart, soul, attitude, comic relief and -- now that Russell Edgington is gone -- all of its quote-worthy snaps if it ever lost Lafayette. He's the cook-turned-dealer-turned-hustler-turned-medium who can bring a laugh or lay down a (warning: curse-filled) bit of wisdom with equal ease, and the show wouldn't be the same without him. -- Ree Hines Which shows would you quit if your favorite characters left?