The Guess Who? game (in the late 80’s) had exactly 5 girls and 19 guys. This was a game of yes/no questions about appearance. If you drew a card w/ a girl on it you were almost sure to lose that round. Women were truly an “unusual subtype”. They were rarer than bald people, people with glasses, and gingers.
The Star Wars Customizable Card Game has exactly one female Imperial: Mara Jade. Female Rebels are half as rare: Leia and Mon Mothma. Female aliens are far more common, though.
While the Warhammer 40,000 fluff contains a good number of female characters, there are very few of those that can be used in-game.
Also, although a number of armies (in particular the Imperial Guard and the Eldar/Dark Eldar) are said to contain large numbers of females, up until recently unless a unit was overwhelmingly female the models wouldn't reflect it. More recent miniatures have started to correct this pattern, with female torsos being available in the Eldar Guardian box sets for example.
Space Marines cannot be female, which justified, as the genetic alterations that turn a human into an Astartes attach only to a y-chromosome.
The Adepta Sororitas army reverses the principle, being composed entirely of warrior nuns (with perhaps the occasional male priest, though these are hangers-on from other branches of the ecclesiarchy, not officially a part of the Sororitas.
Warhammer generally plays the trope straight. Largely justified in that it is set in a fantasy world modeled closely on medieval/early modern Europe. The three elf armies tend to avert the trope, and actually have a number of all-female regimental units (Sisters of Avelorn, Witch Elves, Harpies, Sisters of Slaughter) and characters (Alarielle, Morathi, the Sisters of Twilight), as well as mixed-sex units of regular troops. The human armies play it straight though, with virtually no females in the Empire army at all (the Ice Queen of Kislev used to be, and there are one or two females from the Mordheim range), and the Bretonnian army having female wizards and the Joan of Arc-inspired Paladin Repanse de Lyonesse. As for the rest, one or two female Chaos champions have surfaced over the years (Dechala the Denied and Valkia the Bloody got models), and there have been a Dwarf Queen and a female Ogre Maneater model produced. The Undead tend to have a higher showing of females than most, with the Lahmian Sisterhood of vampires, Isabella von Carstein, Banshees and Tomb Queen Khalida (and the skeletal troops could have been of either sex in life). All Skaven of the sort who make up their armies are male, Skaven displaying extreme sexual dimorphism with the females being little more than gigantic breeding machines left at home in the nests. Finally the Orc, Lizardmen and Daemon armies are completely genderless (apart from Slaaneshi daemons, which are all hermaphroditic).
Infinity seems to be going out of its way to avert this - most troop types have male and female miniatures available.
In AT 43, most armies appear to be equal-opportunity employers going by the background story, but there are basically no models of female regular troops. However, about half the special characters (who are all officers) are female, as are two out of the three released models of medics and one of the three scientist models.
Played entirely straight with the 2014 co-op minis game Myth from MERCS Miniatures. The core heroes are four men and a woman. (They do offer a set of gender-swapped heroes for separate purchase, which lampshades the problem with its relentless pinkness.)
In the Yu-Gi-Oh! game, Burstinatrix was originally the only female Elemental Hero, and it even said so on her original card. (The first version said she was the "only" female among them.) The next was changed because this changed eventually, with new female Elemental Heroes appearing later, like Lady Heat and Poison Rose. (Rampart Blaster too, if you count the Fusion Monsters.)