These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Creator's Pet: While there's no denying he's a talented dancer and choreographer, the constant shilling of Derek Hough (to the point where the judges declared that he and his professional dancer partner deserve to win before the other finalists got their last dance) turned off many fans.
The shilling, plus that he has, thus far, been given reasonable contenders while even the other "wonder triplets", Julianne Hough (his sister) and Mark Ballas (Mark's parents raised Derek and Julianne), have been handed less-than-stellar (or popular) partners.
Zigzagged, Len (the head judge) is not the biggest fan of Derek, sometimes Len's criticism has nothing to do with Derek's partner at all.
Elimination Houdini: Marie Osmond, Master P, Michael Irvin, Cloris Leachman, Billy Ray Cyrus, Bristol Palin, Kendra Wilkinson, Hope Solo, Melissa Gilbert, Bill Engvall, Candace Cameron Bure, etc.
Ho Yay: Ubiquitous. Lest we not forget Mark Ballas and Valentin Chmerkovskiy going head to head.
The recent Madonna dance by Carson Kressley with the Chmerkovskiy brothers is dripping with this. There's no doubt it was intentional.
What likely started it was the season with Steve Guttenberg. One week, his partner, Anna Trebunskaya, had to take a day off. To avoid having him fall behind, her husband, Jonathan Roberts, filled in to help Steve. This led to them performing their all-male Tango (which Tom dubbed "The Man-go,") On the results show that week.
Then there was the (in)famous kiss between Bruno and Donny Osmond.
Just Here for Godzilla: Every season will have someone notable enough to be cast that will encourage viewers to tune in. The reveal that Bill Nye himself will be on Season 17 made a lot of people want to tune in to watch.
The reaction of Hines Ward after he and Kym Johnson completed their Argentine Tango three days after Kym nearly broke her neck.
JR Martinez's rumba to "If You're Reading This." The dance was dedicated to his fellow soldiers who didn't come home from Iraq and Afghanistan. There wasn't a dry eye in the house when the dance was done.
The Scrappy: Every season seems to have at least one contestant who serves as the lightning rod for audience hate.