"They're CROSS! They're crosser than the rest of my face. They're independently cross!"
Breakfast Serials: The British kids' anthology series featured a segment called "Nicechap" about a very nice comic character who twice came to life as a very nice man who spoke in rhyme. Unfortunately, after he retuned to being a drawing for the second time, his creator drew big heavy eyebrows on him in a fit of anger. Then Nicechap came back to life for a third time, and this time he was evil.
Which led to one of the funniest quotes in the whole series:
Walt: I said, 'fuck you!' And your eyebrows!
Buffy the Vampire Slayer: Spike. Made worse by the fact that they're a wildly different color than his platinum-blonde hair. Hell, just look at the picture up on the Badass Decay page.
Degrassi The Next Generation: Manny Santos saw Jane Vaughn swoon over Declan Coyne and asked her, "Who's Johnny Eyebrows?" His actor said he stopped reading YouTube comments of the show promos when the first one was "Eyebrow tweezers. Heard of them?" There's also Sean Cameron. Though his eyebrows are not as big as some of the other examples here, it's lampshaded nonetheless.
Doctor Who: The Twelfth Doctor was literally introduced eyebrows first (and provides the image source), and in "Deep Breath" he calls them attack eyebrows.
Game of Thrones: Little Arya Stark's noticeable eyebrows have not gone unnoticed by the viewers. Daenerys Targaryen's no slouch on the eyebrow department either, mostly because of their expressiveness and how, like Spike's, they don't match her hair.