AP Photo/Chris Miller; NBC

Why should David Letterman consider working more Sarah Palin jokes into the act? What's the hottest vampire saga not named Twilight (or New Moon or any other related sequel)? And did Mark-Paul Gosselaar don Zack Morris' Saved by the Bell sneakers in vain?

The answers—and more questions—in this week's ratings quiz:

1. Why shouldn't Letterman back off on Alaska's governor? Because the more he apologizes, the better his Late Show numbers get. The first time Letterman said sorry—last Wednesday, for those keeping track—Conan O'Brien's Tonight Show edged him in the Nielsen race. By last night, on the occasion of Letterman's second Palin apology, Letterman whooped O'Brien, 4 million viewers to 3.2 million, per estimates.

2. So, it's true then, right, that Palin has been Letterman's Hugh Grant? Wrong—still. Friday night, which, per the calendar, occurred smackdab in the middle of Letterman's Palingate, saw O'Brien win with 4 million estimated viewers to Letterman's 3.8 million. Once Jay Leno had his Hugh Grant breakthrough, the late-night race was all but over. Letterman versus O'Brien is a seesaw battle, except among ad-friendly adults 18-49, where O'Brien has most of the weight.

3. Why is HBO digging the undead? Because True Blood is its first sign of original-programming life since the death of The Sopranos. According to the network, the Anna Paquin vampire series' second-season premiere scored 3.7 million viewers, the most for an HBO show since David Chase abruptly cut to black on the final Sopranos in 2007.

4. Did Raising the Bar get a Zack Morris bump? Sort of. On one hand, the TNT series' second-season opener was up over its first-season average, with 3.6 million viewers and a top 10 finish among cable dramas, per the latest Nielsen rankings. On the other hand, the legal series blew half of its top-rated lead-in, courtesy of the returning The Closer (cable-best 7.1 million), plus Gosselaar has to live with clips of his adult self in acid-washed jeans chatting up Jimmy Fallon.

5. What was bigger: the deteriorating state of affairs on Jon & Kate Plus 8 or the kids-of-divorce fantasy, The Parent Trap? It was close, but an all-new Jon & Kate (4.3 million, tops for a cable reality show) just did beat an umpteenth Disney Channel broadcast of 1998's The Parent Trap (4.1 million, tops for a cable movie), possibly indicating that the Gosselin children simply don't have enough cable boxes in their home to decide Nielsen wins.

6. Name one positive thing to come out of the Gosselin mess. Well, if you work for American Chopper, you are stoked because you got 2 million viewers for an all-new episode featuring, yup, Jon and Kate and dysfunctional company.

7. Which show burned Burn Notice? Better make that, shows—plural. A week after finishing atop the cable rankings, Burn Notice (5.2 million) stayed strong, but fell to third among prime-time scripted shows, behind the aforementioned The Closer and, more surprising, its own newbie companion, Royal Pains (5.6 million). Other cable standouts: In Plain Sight (4.3 million), Law & Order: Criminal Intent (4.1 million) and Army Wives (3.7 million).

8. Which show won cable's tween wars? An all-new Hannah Montana (3.5 million) topped an all-new iCarly (3.3 million). The hanging-in-there JONAS (3.1 million) outdrew its lead-in, Sonny With a Chance (3 million).

9. Why do Pushing Daisies fans owe Bob Saget and Ian McShane thank-yous? The returns of Saget's canceled sitcom, Surviving Suburbia (1.8 million), and McShane's canceled drama series, Kings (1.3 million), prevented Pushing Daisies (2.2 million) from leaving this world as the week's least-watched all-new show on the big four broadcast networks.

10. What was TV's biggest—and also tallest—show of the week? The Kobe Bryant-led NBA Finals dominated the broadcast standings, leaving little room for summer series to crack the top 10. The Wednesday edition of So You Think You Can Dance came the closest—it finished 11th, with 8.7 million viewers.