In the words of famed "Casablanca" piano man Sam, "A kiss is just a kiss." Particularly when it comes to memorable — and sometimes awkward — moments at MTV awards shows.

There have been so many kisses at the network's big events over the years that at least one big smooch can now be expected at each show. Sunday's MTV Movie Awards proved to be no exception, as two of the evening's most talked-about moments featured locked lips between two very pretty ladies and two not as pretty dudes. The kiss between Sandra Bullock and Scarlett Johansson has inspired us to highlight some of the channel's surprising yet sexy moments over the years, while Jonah Hill and Russell Brand's smooch has had us recalling some surprising yet unsexy bits.

At 2003's Video Music Awards, the most talked-about moment was hands-down the three-way girl-on-girl-on-girl kiss between Madonna, Britney Spears and Christina Aguilera. It wasn't enough that the year's two dominant teen pop princesses were performing with the MTV music legend, oh no. Midway through their "Like a Virgin" medley, Madonna leaned to her right and shared a steamy kiss with Britney. Then she leaned to her left for a smooch with Aguilera.

"Twilight" fans were pretty frustrated when their favorite movie couple, Robert Pattinson and Kristen Stewart, teased fans by almost-but-not-quite smooching to celebrate their Best Kiss win in 2009. That brief encounter added fuel to the "are-they-or-aren't-they-a-real-life-couple" fire for their fans to obsess over and analyze for months afterward. This year, after faking awkwardness for a while, they finally locked lips, if only for a few seconds, turned away from the crowd.

KStew and RPattz were good, undoubtedly. But "Notebook" stars Ryan Gosling and Rachel McAdams were great. Not only is the kiss that sealed their 2005 Best Kiss nomination and eventual win one of the most talked-about Best Kiss moments in movie history, the two stars took MTV Movie Awards acceptance "speeches" to unprecedented swoon-worthy territory. Upon hearing their names called, Gosling and McAdams walked up to the stage together, parting ways at the top of the stairs to take places at opposite ends.

They paused to seemingly loosen up for something big. McAdams shed her jacket and adjusted her strapless top; Gosling did a couple of warm-up jumps and then crooked his finger across the stage at his co-star, whereupon they met in the middle for a very effective reenactment of their movie's famous moment (and quite possibly the greatest Best Kiss moment in MTV history to date).

Not all kisses are created equal, however. Some MTV kisses would be better erased from collective memory and video vaults. Will Ferrell and Sacha Baron Cohen — very possibly in an attempt to spoof McAdams and Gosling — accepted their 2007 win for Best Kiss with gusto. When the "Talledega Nights" stars commit to something, they do so wholeheartedly, sealing their moment with a very sloppy, drawn-out smooch.

The most eyebrow-raising moment was the infamous kiss between newlyweds Michael Jackson and Lisa Marie Presley. The couple had already made waves with the release of Jackson's awkwardly intimate video for "You Are Not Alone," in which both Presley and Jackson appear half-naked in a bedroom setting. They upped the ante completely when they opened the 1994 Video Music Awards. "Nobody thought this would last," Jackson said, and then embraced his wife for a lengthy, surprise smooch.

Relive the wildest, funniest and most-jaw-dropping moments of the 2010 MTV Movie Awards, watch revealing red-carpet interviews and get exclusive movie clips after the show at MovieAwards.MTV.com.