Testosterone Brigade

The Spear Counterpart to the Estrogen Brigade, the Testosterone Brigade is an enclave of male fans within a traditionally female-dominated (or at least gender-neutral) Fandom. While they dislike the Female Gaze or the Mr. Fanservice, it's very likely that they were pulled into the series in the first place because of a (preferably attractive and sexy) female character. Depending on the series, they may view it as a Guilty Pleasure due to the amount of female fans. Occasionally, as with an Estrogen Brigade, both sides will butt heads over largely superficial reasons, with buckets of opposite-sex awkwardness, which can get defensive. It should also be noted that not all male fans within such a fandom are necessarily of the Testosterone Brigade.

A Testosterone Brigade is easily attracted by hints of Les Yay or by Fan Service from main characters. See also Multiple Demographic Appeal. When the producers or creators notice this demographic and make a "girly" show that's actually aimed at men, it's What Do You Mean It's Not for Little Girls?.

Anime and Manga

 * Most male fans of Kaichou wa Maid-sama like it because of Misaki Ayuzawa, the female lead, and her dynamics with Usui.
 * Fruits Basket has a ton of male fans, but mostly because of the story/characters, though they certainly would've enjoyed some more eye candy
 * Sailor Moon. While it is primarily a shojo anime, it actually has quite a bit of a male following as well, with all the Sailor Senshi being really hot, kickass action girls. There are Testosterone Brigades for approximately all ten of the female leads.
 * Magical Girl series in general, really, to the point where some modern series are written primarily for a slightly older, mostly male audience. Puella Magi Madoka Magica and Lyrical Nanoha are among the most successful examples.
 * The large male fanbase of the animé classic Cat's Eye, which features three highly attractive, highly trained action girls. They are essentially a Japanese version of Catwoman, sans the whip and cat-themed suit. All three are sisters, each one having their own Brigade, and the show can be considered the Darker and Edgier ancestors of Totally Spies!.

Live Action TV

 * The L Word, as was inevitable for a show about a bunch of very good-looking lesbians. It pandered generously to straight males through extensive sex scenes, making one of the girls bisexual (which ensured at least some scenes would include a straight guy), featuring mainly straight guys in the supporting cast and reducing gay guys to extras. Ilene Chaiken publicly claimed that the show would never have been made if it hadn't pandered to the Testosterone Brigade—and unfortunately, she's probably right.
 * Sex and the City. It's a show about four sexy older women who like to have sex and talk about it—and this being HBO, they don't cut away from the nudity. While its male fanbase is often stereotyped as being composed primarily of Camp Gay men who watch it for the fashion, during its prime it also had a very large contingent of straight male fans, as it featured a ton of female skin and enough of the male perspective (at times) to occupy straight men's interest.
 * The same could be said of True Blood and other female-targeted HBO shows, for much the same reason.
 * Desperate Housewives. Its description on this wiki even describes it as "not a porn mag, but a US TV drama." At the height of its popularity, ABC even ran an ad with a guy admitting he watched it... and (unconvincingly) claiming that it was for the story. Riiiiiight.

Music

 * This has been the rule for most female pop/R&B idol singers and girl groups within the last 30 years. The girls come for the music, the boys come for the ladies singing it. Oftentimes, female musicians go for Hotter and Sexier images (or have it pushed onto them) specifically to invoke this.
 * Kate Bush has a very large Testosterone Brigade among her fanbase.
 * Female-fronted symphonic metal bands such as Nightwish, Epica and After Forever. While metal music as a whole already has a very large male following (and an Estrogen Brigade), a good number of these bands' fans are listening and going to concerts for a bit more than just the music.

Professional Wrestling

 * Female wrestlers in general get this, often to their detriment. In many cases, pro wrestling companies, recognizing this appeal, have dropped all pretense of their women's divisions being about athletic competition in order to use them to supply as much cheesecake as possible.

Sports

 * Race car driver Danica Patrick, who has parlayed her Testosterone Brigade into both a NASCAR career and modeling work. She's a damn good racer, but most people seem to best know her for her GoDaddy ads.
 * The strange case of high school pole vaulter Alison Stokke.

Western Animation

 * When a show is packed with as much Fetish Fuel as Totally Spies!, it's bound to pick up a lot of male fans along the way.
 * Kim Possible. Have you seen some of the fan art of Deviant ART?
 * What male fans exist of the Disney's Tinkerbell movies tend to be a Testosterone Brigade, as there is a surprising amount of Fan Service in the films.
 * The famous "Brony" fanbase of My Little Pony Friendship Is Magic. Also a rare example that doesn't use Fan Service. Bronies actually started out as an ironic fandom before suddenly exploding onto the online svene in 2011 and 2012.