It's that time of year again, when everyone starts looking back over the past year and compiles 'Best of' and 'Worst of' lists. Twitter's been unveiling its annual 'Year in Review' since Thursday and has just published its 'Hot Topics' lists.

Uber-Twitter user Charlie Sheen's clearly still winning online: Last week AOL announced that Sheen was our most searched-for celebrity in 2011, and now he's claimed the top spot in the Twitter "Actor" Hot Topic.

Plus, one of his stranger obsessions -- #tigerblood -- came in at Number 2 in the "Hashtags" category (just behind #egypt).

Check out who and what else made the cut after the jump.

MTV has announced it will be airing a one-hour tribute celebrating the life of the late 'Jackass' star Ryan Dunn. 'The Ryan Dunn Tribute' Special is scheduled to air on Mon., Nov. 28 at 10:30PM ET on MTV.

Dunn, who died in a high-speed car wreck in June of 2011, was a beloved member of the 'Jackass' crew, and was featured prominently in their TV series and film franchise.

"It's a surreal thing to undertake, doing a tribute to our brother Ryan's life. I still can't believe he's gone but we wouldn't trust anyone else with this, so we are doing the best we can for Ryan, his family, friends, and everyone who loved him," Johnny Knoxville said in a statement.

Everyone's favorite TV troublemaker, Michelle Trachtenberg, is set to cause some serious trouble for Nancy Botwin on 'Weeds' this season.

Like Mary Kate Olsen before her, Trachtenberg will play a pot dealer on the Showtime series -- but her character will be one of Nancy's rivals, not one of her coworkers. Look for the actress also known as Georgina Sparks to pop up in two episodes this season.

'Weeds'' seventh season premieres tonight at 10PM. Check out AOL TV's interview with star Justin Kirk, then figure out which quirky Showtime woman you're most like in our handy flowchart.

In other TV news ...

After 'Jackass' star Ryan Dunn's tragic death yesterday morning in a car crash that also took the life of one of his friends, it appears even the most unlikely of celebrities are weighing in on the matter.

In response to the sad news and the image Dunn posted to his Twitter account (which has since been taken down) showing him and two friends sitting around a table with beers at their side just three hours prior to the fatal car crash, Pulitzer Prize-winning film critic Roger Ebert took to his own Twitter account at 3PM yesterday to post the message: "Friends don't let jackasses drink and drive."

As you can probably imagine, that hasn't exactly sat well with everyone, especially those who knew Dunn best.

Hit the jump to see how the Twittersphere responded to Ebert's comments.

And one of the new 'Bachelor Pad' contestants is ... William, the cell phone salesman!

Yep, the guy who made Ashley cry during an awful date will be joining Jake Pavelka, Vienna Girardi and various other 'Bachelorette' and 'Bachelor' castoffs in the 'Pad.' Entertainment Weekly confirmed the news.

Two more mystery contestants will be revealed before the August 8 premiere. Paging Bentley ...

Check out a full cast list here.

In other TV news ...

'Jackass' star Ryan Dunn died early this morning in a Pennsylvania car crash. April Margera, mother of fellow 'Jackass' daredevil Bam Margera, confirmed to TMZ that Dunn was killed in the car wreck that also killed one other person who has yet to be identified.

The 34-year-old was a part of the 'Jackass' film franchise -- often pulling off eyebrow raising stunts to the delight of his fellow thrill-seeking buddies.

Just hours before his death, Dunn tweeted photo of himself and two pals -- documenting their night out, beer and cigarette in hand.

A photo of the charred wreckage of the car was posted on Twitter and Flickr, apparently by the towing company. The image shows the extent of the fire that must have engulfed the vehicle.

Two members of the 'Jackass' crew took to the stage on 'Minute to Win It' (Wed., 8PM ET on NBC) and proved themselves to be real class acts, trying to raise money for two worthy charities. If you're going to go on television to raise money for charity, why not have fun doing it? And it was clear that Ryan Dunn and Steve-O were having a blast with Guy Fieri and these wacky games.

No one could argue that the games on 'Minute to Win It' are so outrageously simple you can't help but have a blast doing them. Balancing four hangers on the tips of their hooks on a clothesline is brilliantly stupid, and that's what makes the show so fun.

It was a charming display through and through, reminding us that these guys are more than the crass things they do in their 'Jackass' performances. These are genuinely humble and decent human beings with huge hearts.