Of all the genres in anime, the magical girl genre is one of the most over looked and here are five anime that fell by the wayside.
Saint Tail
The daughter of a stage magician and retired thief steals art to give back to their rightful owners, it takes elements from Cats Eye and functions as the predecessor for Card Captor Sakura, utterly charming with an adorable lead and beautiful setup that far exceeds it's time period, Saint Tail is a must for magical girl fans.
Kamikaze Kaitou Jeanne
Arina Tanemura's take on the magical girl genre with her extreme wide eyed style of animation blending heavy moments of psychological themes with a magical thief plot, best remembered for arguably the best transformation scenes in the genre.
Full Moon
Tanemura again this time going heavier on the psychological elements and heavy references to suicide is Full Moon, a take on the magical idol genre, it's worth noting that despite what the audience gets put through, the ending is always a happy one. This was breaking boundaries long before Oshi no Ko.
Pretear
A loose blend of Snow White and Cinderella elements, with pretty boys transforming into the lead girls costumes, (don't think too much about it) the lead is tasked with saving the natural world of leafe with the help of her seven knights, probably one of most fiercely independent leads seen in the genre long before the trend of strong female leads were needed for absolutely everything.
Wedding Peach
Written off as a Sailor Moon clone thanks to the era it came out, Wedding Peach is alot closer to Precure in terms of content, predating it by a decade and it's been referenced more times than Sailor Moon with the wedding dresses and the champagne drinking scene having both been referenced in Pokemon of all things, lead character Momoko is also one of the main reasons why most lead magical girls are pink coloured.
Honourable Mentions
Corrector Yui - Megaman.Exe if it were a magical girl series, it's so obscure that no one remembers it.
Nurse Witch Komugi - A spinoff of a horror anime, it's as silly as it sounds.
Magical S Project - The official Pretty Sammy tv series spun off from the Tenchi Muyo franchise, way better than it has any right to be.
My Wife is a Magical Girl: Bewitched Agnes - An example of an adult magical girl series with an adult lead, heavily influenced by the American 60s sitcom Bewitched, worth your time if you can find it.
Sally the Witch - If only for historic purposes, this is often cited as the first magical series.