“Dancing with the Stars” Season 7 has been a tough one, with more injuries and less 10s than ever before. It’s also produced many memorable moments (both good and bad), as the show takes more risks and pushes the couples to their absolute limits. Click through this slideshow to see my picks for the best and worst performances of the season as we head into the semi-finals.Monday, November, 17, 2008, 6:17 PM

WORST: Kim and Mark’s Mambo, performed Week 1 to Sir Mix-a-Lot’s "Baby Got Back," was too slow and boring to be considered an actual train wreck, but it was a disaster nonetheless. You may wonder, how can you go wrong with Kim Kardashian dancing to “Baby Got Back”? Ask Kim’s poor partner Mark Ballas, who danced like the Tasmanian Devil around her in an attempt to distract the disappointed audience. ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

BEST: Brooke & Derek’s Samba, performed Week 4 to the quirky song "Hip Hip Chin Chin," may have only scored the frontrunner a 26, but it was the first dance of Season 7 to get me fired up for some real competition. Derek’s choreography was inspired, and Brooke was so drop-dead sexy that she prompted a “too erotic” complaint from grumpy Len, a request for “a smoke” from Bruno, and a prediction from Carrie Ann that Brooke would “go all the way” to the finals.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

WORST: Rocco & Karina’s Samba, performed Week 4 to “I Go to Rio,” was as klutzy and embarrassing as all of his dances, but it seemed especially bad given that he would have been eliminated the week before had Misty not ruptured her tendon and dropped out of the competition. Given the immediate danger Rocco was in, I expected him to rise to the pressure and show a little bit of improvement. But no.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

BEST: Lance & Lacey’s Tango, performed Week 4 to Rihanna’s “Disturbia,” was the routine where the rebellious couple finally partnered their wild originality with legitimate technique and executed a brilliant performance. It was sick in all the best ways, with intense and sharp moves in perfect unison, and it even inspired Len to nickname Lance “Sir Dance-a-lot.”ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

WORST: Lance & Lacey’s West Coast Swing, performed Week 5 to Rihanna’s "Breakin' Dishes,” should have been an explosive performance, but instead it seemed to be stuck at half-volume and even included the only slip and fall of the season. Chalk this one up to Lance’s lack of confidence getting the best of him, dancing in front of millions with Lacey, who is the World Swing Dance Champion. His performance shut down about mid-routine, and Lacey took heat from the judges for outshining Lance. Of course she was going to outshine Lance! All of the professional female dancers outshine their stars, and this particular star didn’t appear to want to shine on this particular night.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

WORST: Cloris & Corky’s routines, performed week after week (despite my numerous complaints), were so atrocious that I can’t pick just one of them as the worst -- they were all bad. Corky did his best to work some dancing into the mostly comedic routines, but not enough for them to be legitimate competitors. Sure, you can’t knock a gal for trying, but the shenanigans went on for far too long.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

WORST: The group Hip-Hop routine, performed Week 6 to "It Takes Two" by Rob Base and DJ E-Z Rock, reminded me of a wedding reception where the middle-aged people bust out their hazy old-school moves on the dance floor just to embarrass their kids. It was bad -- as in not good. And Susan Lucci put the cherry on top of this mess as she shamelessly rubber-necked to mimic whomever she was dancing closest to, always about four beats behind. It was really bad, as in totally not good.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

BEST: The group Paso Doble, performed Week 7 to “Rocks” by Primal Scream, had such a dramatic and perfectly timed build that it literally made me leap off of my couch and cheer. This bold routine was an explosion of power, with squared shoulders and twirling blue skirts, and it just kept getting bigger and bigger until Brooke and Derek hit the floor at what seemed to be 1000 RPMs. It was incredible! And the team’s sheer jubilation following the number was one of my favorite moments of the season.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

BEST: Brooke & Derek’s Foxtrot, performed Week 7 to Sarah Vaughan’s "Lullaby of Birdland," scored the only perfect 30 of the season thus far and was just … perfection. What more can I say? It was the most flawless performance I have ever seen on “DWTS” between a star and their professional. During training that week Derek told Brooke that there were moments he felt like he was dancing with a professional, and during judging Carrie Anne agreed that Brooke was “as good as our professionals.” The former model set the bar pretty high from the start of the season and didn't let me down once (I even loved her Rumba).ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM

BEST: Warren & Kym’s Tango, performed Week 8 to the theme song from “Peter Gunn,” was a perfect example of why Warren will be in the finals of this season’s competition. A man his size should not be physically capable of the swiftness he brings to the ballroom every week, and Kym’s fun and dramatic Tango showed off all his right moves.ABC/Kelsey McNeal - Monday, November, 17, 2008, 6:17 PM