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.
YMMV: Totally Spies!
Base Breaker: Mandy. On the one hand, Mandy is pretty much the textbook example of the Alpha Bitch, being a Jerkass and sporting an annoying voice to boot, not to mention having a Karma Houdini moment from time to time. On the other hand, a lot of fans actually like Mandy, and not just in the Draco in Leather Pants kind of way, using the numerous times where she attempted to treat the girls nicely as evidence that she's not a total Jerkass. She's one of the most frequently shipped characters in the fandom (usually with Clover or Sam), and some even find her "annoying" voice sexy in a weird sort of way (it helps that she's voiced by Jennifer Hale).
Britney and Blaine get their fair share of this too, Britney has simultaneously been lambasted for being a Mary Sue and praised for being a likableMary Sue who gets Hidden Depths later on. Blaine gets bashed for his Sickeningly Sweethearts relationship with Clover, though some fans do see him as pretty much the perfect match for Clover, as long as you don't ship her in one of her many Les Yay pairings.
Complete Monster: Helga Von Guggen. It's explained in the most PG way possible that she intends to skin people alive and make their flesh into clothes in order to save money.
Draco in Leather Pants: Tim Scam, oh so very much. Mandy to a lesser extent, though it's at least feasible that she could stop being a bitch someday, and it's interesting to pair her with one of the main girls. Scam is straight up evil and he gets paired with Sam in literally hundreds of fanfics.