Sailor Moon (1st Season)

Season/Arc One The Dark Kingdom Arc spans over volumes 1-4, (acts 1 through 13), in the manga, and runs through episodes 1-46. The first time you read it, it's almost like a roller coaster ride. You start with Tsukino Usagi, who must morph into Sailor Moon to fight monsters, with the help of her advisor Luna and a mysterious man who goes by the name Tuxedo Kamen . After she gains friends and allies, (Sailor Mercury ,Sailor Mars , Sailor Jupiter ), Luna tells her that she must find the Princess of the Moon. They eventually find out that their enemy, better known as the Dark Kingdom, is also after the mysterious Silver Crystal / Ginzuishou. In their search for the Moon Princess, they meet Sailor V / Sailor Venus and her feline advisor Artemis, and learn that 1000 years ago, they had lived past lives on the Moon. As the story continues, Usagi makes another transformation: from a selfish crybaby to a beautiful soldier, she finds the strength in herself and her friends, to defeat Queen Beryl and Metallia, once and for all. The senshi pray for peace, but it seems that their battles are just beginning...

Key differences between anime/manga version:

Overall, the manga is a lot darker
The characters are more mature
Generals die differently
More filler / random episodes
Mamoru does not throw roses in the manga; but he is known to have some present in colored manga illustrations
Kunzite and Zoicite are lovers in the Japanese anime version; this is not so in the manga, or it is not explored at all
Nephrite does not fall in love with Naru in the manga
In the past, Princess Serenity commits suicide in the manga, in the anime, she's killed by Queen Beryl
In the manga, the senshi use their star power to awaken Sailor Moon and Tuxedo Mask who are incased in the Silver Crystal, which is inside Metallia
In the anime, the inner senshi die by the hands of the Doom and Gloom girls
In the final battle against Queen Metallia, Mamoru becomes blind, and does not die
Sailor Moon tries to commit suicide, thinking they are doomed to the same fate they suffered in the past. However, she stabs the pocket watch Tuxedo Kamen gave her instead of her heart.
In the anime, Sailor Moon fights a super-powered Queen Beryl (merged with Metallia) instead of Queen Metallia. In the manga, Sailor Venus kills Beryl in the past and the present with the Holy Stone Sword.
After the battle, the senshi don't lose their memories, unlike the anime version

Manga: Original tankoubon volumes 1-4:

Act 1 - Sailor Moon
Act 2 - Sailor Mercury
Act 3 - Sailor Mars
Act 4 - Kamenfutoukai - Masquerade
Act 5 - Sailor Jupiter
Act 6 - Tuxedo Kamen
Act 7 - Chiba Mamoru
Act 8 - Sailor V
Act 9 - Princess
Act 10 - Moon
Act 11 - Endymion
Act 12 - Reincarnation
Act 13 - Petite Etranger

Anime Series:

01. Crybaby Usagi's Magnificent Transformation
02. Punish Them! The House of Fortune is the Monster Mansion
03. Mysterious Sleeping Illness, Protect the Girls' Hearts in Love
04. Usagi Will Teach You How to Lose Weight!
05. A Monster's Scent! Chanela Steals Love
06. Protect the Melody of Love! Usagi is Cupid
07. Usagi Learns a Lesson! The Road to Stardom is Tough
08. Is the Genius Girl a Monster? Brainwashing School of Terror
09. Usagi's Misfortune! Watch Out for the Rushing Clocks
10. Cursed Buses! Fire Warrior Mars Appears
11. Usagi vs. Rei? A Nightmare in Dreamland
12. I want a Boyfriend, Too! A trap on a Luxury Cruise Ship
13. Girl Power! The End of Jadeite
14. A Powerful New Enemy! Nephrite's Evil Crest
15. Usagi is Frantic! Rei's First Date
16. Dream of a White Dress! Usagi Becomes a Bride
17. Is Usagi a Model? The Focus of the Monster Camera
18. Shingo's Innocent Love! A Sorrowful French Doll
19. Usagi is Thrilled! Tuxedo Mask's Love Letter
20. The Summer! The Ocean! Our Youth! And a Ghost, Too
21. Protect the Children's Dreams! Friendship Linked by Anime
22. Romance Under the Moon! Usagi's First Kiss
23. Wish Upon a Shooting Star! Naru's Pure Love
24. Naru's Cry! Nephrite Dies For Love
25. Jupiter, The Brawny Girl in Love
26. Bring a Smile to Naru's Face! Usagi's friendship
27. Love for Ami?! A Boy Who Can Predict the Future
28. Illustrations of Love. Are Usagi and Mamoru Getting Closer?
29. Total Chaos! The Messy Square Relationship
30. Grandpa Goes Crazy, Rei's in Jeopardy
31. Loved and Chased! Luna's Worst Day Ever
32. Umino's Resolve! I'll Protect Naru
33. The Last Sailor Warrior, Sailor Venus Appears
34. The Sparkling Silver Crystal! The Moon Princess Appears
35. Memories Return! Usagi and Mamoru's Past
36. Usagi is Confused! Is Tuxedo Kamen Evil?
37. Aim to be a Princess? Usagis' Weird Training
38. The Snow1 The Mountains! Our Friendship! And Of Crouse, A Monster, Too
39. Paired With a Monster?! Ice Queen Mako
40. The Legendary Lake Monster! Usagi's Family Ties
41. I Won't Run From Love Anymore! Ami and Mamoru's Showdown
42. Sailor Venus' Past, Minako's Tragic Love
43. Is Usagi Going It Alone? The Sailor Warriors Get Into a Big Fight
44. Usagi's Awakening! A Message From the Distant Past
45. The Sailor Warriors Die! The Tragic Final Battle
46. Usagi's Everlasting Wish! A New Reincarnation