10. Joel Grey, Grey's Anatomy
While there are always patients of the week traipsing in and out of the halls of Seattle Grace, we usually have a hard time remembering most of them. But Joel Grey was an exception (and not just because we're massive theater geeks), playing the (presumed) dementia-ridden former mentor to Izzie. And while we're down on Izzie, it was nice to see her briefly doing something for someone other than herself. Their scenes together were actually sorta sweet.

9. Edward Norton, Modern Family
Elizabeth Banks was certainly a fun guest star as a brash party girl, while Shelley Long was fabulous as terrifying matriarch of this wild clan, but it was Edward Norton in crazy '80s garb that really stood out this season so far. In quite a departure from his typically intense film work, he played the bass player from Spandau Ballet. Their famed tune, "True," was supposedly Phil and Claire's song, so she invited him to perform a private concert in her house as an anniversary present for Phil. Norton really dove into this character, strange accent and all, and we laughed through every minute of it.

8. Betty White on 30 Rock
It wasn't a big part, but Betty White made a brief-yet-memorable appearance in the episode "Stone Mountain," when Tracy Jordan was scared that he was going to be the third to die in a questionable celebrity "Rule of Three." Hoping that he could find a third to take his place, he rang up Betty White, with whom he once co-starred in a rapping grandma movie. (Jordan played the rapping grandma.) After he asked her about her health and other life-threatening activity, White quickly sussed out that it was a "Rule of Three" call, and Betty got Ugly: "Nice try, Jordan. But I am going to be at your funeral. I will bury you!" Do not mess with the Betty.

7. Louis C.K., Parks & Recreation
One of the best comedians in the land hopped on the Leslie Knope caboose this season, and not only did their brief, sweet courtship result in a lot of great moments (Louis's description of his attraction to her in police report format in particular was hilarious, and his effort to learn who all the women on her office wall were was all kinds of heart-melty), it also garnered one of the best episodes of the season, Practice Date, in which Ann took Leslie out on a series of "practice dates" and we learned what a freak of nature Leslie truly is. Always appreciated, Louis. Always appreciated.

6. Leonard Nimoy, Fringe
When you wait all season to meet the most ominous character in the Fringe-verse, it better be somebody impressive. Leonard Nimoy was a casting coup for the sci-fi guilty pleasure, and the perfect choice for the mysterious, (probably) nefarious William Bell. It didn't even really matter that he didn't stick around long, and he didn't tell us much, and that the show has essentially forgotten all about The Pattern that he's supposedly responsible for -- he's Spock, and he lives in the Twin Towers in an alternate universe, and that blew our minds more than anything we've ever seen on this already insane show.

5. Gilles Marini, Brothers & Sisters
His guest appearance was short-lived, because Brothers & Sisters tends to rival Heroes in terms of self-destructiveness, but Gilles Marini was hands-down the best thing to happen to the show in years. His impromptu dance lessons brought both some fun (Justin's wedding lesson), and some much-needed poignancy (Nora's waltz lesson by the pool) back to the show, and everyone ogling his abs and accent was the kind of gleeful Walker silliness we haven't been treated to since Scotty was put on trial for calling a highway patrolman "Little Miss Officer" in Season 2. They found a silly Sarah-is-an-oblivious-idiot way to excuse him from the show, and we're still heartbroken over it.

4. James Earl Jones, House
The script for his evil dictator storyline may have been a bit weak and preachy, but if anybody can sell a weak and preachy script, it's fricking James Earl Jones. Having Darth Vader as a House patient was just downright exciting, no matter what the circumstances. And he wasn't just a monster of the week -- his murder at the hands of Chase was the catalyst for Cameron divorcing him and leaving PPTH (and the show), which gives him the rare distinction of dying despite House's attentions, and also having an influence on the Cottages past the week his name was in the credits.

3. Kristin Chenoweth, Glee
It made absolutely no sense at all to have April Rhodes as part of New Directions, but who cares? Chenoweth was at her belting best and we were thrilled. She was a funny, drunken, shoplifting former show choir performer desperate for attention and a bit of her former glory. She showed up Rachel during a performance of "Maybe This Time," taught the other girls some fabulous tricks of her trade, sang "Alone" with Will and made us laugh with her rendition of Carrie Underwood's inappropriate-for-high-school song "Last Name." Such a pleasure, though it did make us miss Pushing Daisies all over again.

2. Summer Glau, Dollhouse
We were still reeling from the cancellation of Terminator: The Sarah Connor Chronicles (we bottle up our feelings for a long time) when we heard that Summer Glau was going to show up on Dollhouse. We knew the reunion of Glau and Whedon would be a thing of beauty, but we had no idea. As Bennett Halverson, the genius programmer at the Washington, D.C. Dollhouse, Glau was a calculating ice queen who turned on the shy-girl charm to keep the visiting Topher Brink off his guard, and then tortured Echo for kicks. Turns out she and Echo have history, with Echo once leaving her with her arm pinned under some debris, so Bennett put those memories in Echo's head, rendering Echo's arm useless, then smashed her own head into a monitor to make it look like Echo beat her up and escaped. This is not the River Tam we remember, but we like it.

1. The Seinfeld Cast, Curb Your Enthusiasm
Not only did we get a more satisfying ending to the Seinfeld saga with the reunion episode within the Curb finale, but the appearances of Jerry Seinfeld, Jason Alexander, Julia Louis-Dreyfus and Michael Richards really made this season of the show the most watchable in years. In fact, Curb had completely fallen off our radar, but seeing the old gang back together trying to deal with the minutia of life (coordinating tips! Blackberries!) and the merits of doing a reunion without looking like they were selling out for the cash was just delightful and we would have easily watched another 10 episodes of the HBO series if they'd aired.