Soul Eater (TV)

Many character names are puns on other well known characters or works: Blair (witch); Sid Barett (Cid & Barett from Final Fantasy VII); Dr. Franken Stein; Lupin (Lupin III); Al Capone (Al Capone); Crona (Chroma from Phantom Brave?)

The name "Sid Barett" is most likely a tribute to Syd Barrett, the late, highly eccentric founder of Pink Floyd.

In 2005, before the series received an anime adaptation, Square Enix released a Drama CD entitled "Soul Eater: Tokubetsu Shakaika Kengaku", featuring a voice cast different from the TV series. Of the cast used for the CD, only Yumiko Kobayashi (Black Star's voice actress) reprised her role for the anime.

Episode 28 seems to pay a tribute to the film Yojimbo aka The Bodyguard starring Toshirō Mifune.

The names of Kid's twin guns are Patty and Liz Thompson. I would have to assume this is a reference to the 80's new wave/synth group, Thompson Twins.

In episode 4, when Black Star get smashed into the ground a "cross explosion" can be seen. This is a reference to neo genesis evangelion when an EVA or an angel gets destroyed.

In episode 9 at 7:24, the title on the book Maka reads, roughly(?) says "Gangan", the same title as the manga magazine "Shonen Gangan" that Soul Eater was serialized in.

In episode 10 the Fay Blade Masamune quotes the philosopher René Descartes by saying "I think, therefore I am. Therefore I devour."

In episode 12, the dream that Soul Eater has is uncannily similar to Twin Peaks' red room scene with the backwards talking dwarf.

In episode 14, Spirit/Death Scythe does a Kamehameha pose while "transmitting" a good luck aura to Maka.

In episode 27, between 2:44 and 2:51 we see quite a few books whose titles involve Excalibur's name (spelt as Excariba). These titles are: "First Excariba", "Breakfast with Excariba", "Brunch with Excariba", "That's Excariba", ".. with Excariba"(the first word is not visible, and next to that book is an other one Excariba book but half of the title is not visible), and a book whose title is "Soul Eater"

In episode 29, the little girl Rachel watches the tv show of herself climbing a ladder up a tree to get an apple and of Medusa in snake form sitting on the tree. This is a similar representation of the Bible's Eve taking the forbidden fruit and the Devil's snake form telling her do to so.

In episode 37, it shows arrows pointing at Stein-sensei's house. Most likely showing some sort of premonition, related to Medusa, or something ALREADY happen thanks to her(The snake in Marie-sensei).