Gosick

MC Female Detectives are quite rare. Here's a collection of them.
Some are less realistic detectives, e.g. in a magic show.
Only the most prevalent anime (meaning an anime not difficult to find) that they are an MC in is included in this list. This excludes sequels and such.

Series that range around 11 episodes to 26 episodes and have already reached their finale. Taking into account 2nd parts for the 26 ones.

Anime series that are great and underrated.

must have a big brain to watch this

All these romance shows will make you feel good in some way. Some might even make you cry.

Royal family members, aristocrats and children from really rich and influential families

A compilation of romance anime that doesn't include a school setting.

This stack is an ultimate starter pack if you are looking for anime with genius protagonists or characters with considerably high IQ. If mind games and intelligent moments are your go-to interests, this is the perfect stack for you.

For anime with sequels, only the first seasons of each have been included in the stack. The genres include (but are not limited to) psychological, mystery, isekai, sports, and romance/drama.

Long-running shounen anime have not been included in the list, except Detective Conan (in case you are looking for Bleach or Fullmetal Alchemist - yes, this is according to Aizen's plan too).

Part 2 of the series is in progress. Watch this space for updates ;)

Anime set in aforementioned time periods. Some of them are technically not historical but have the vibes.
Only from what I have already watched, so sorry for a small number.
(Possibly mild spoilers)

Anime with lolis as main focus or main characters.

This is the best combination to ever exist.

Anime with girls, who really, really, really, really, REALLY like someone, but too tsundere to admit it, if that’s what you want.

These are all romance anime from the shounen demographic. These are all anime I’ve enjoyed one way or another. Since this is the shounen demographic, there’s a lot of fan service and ecchi shows in here. I’m not a huge fan of that but there are some shows I liked regardless. I hope you find something new to watch!

Classic mystery whodunnits or police detectives solving cases involving murder, theft, etc. with a limited number of suspects. Mostly episodic rather than a full series with only one plot/case. Some listings with supernatural elements but only if it fits the 'detective' part of it.

Don’t you hate it when the mystery is just kind of the side genre, and it’s mainly focused on the horror and such? Here are some series that you can actually rack your brain to and get mind blown when the truth is revealed.