A collection of quality mods which I feel best represent the capability of the modding community and some of the history behind those mods.

Digsite is a collaboration between Halo Studios (formerly 343 Industries) and hand picked community modders to restore cut content to the Master Chief Collection.
Members include: Kenneth "Tzeentch" Peters, Sean "Kornman00" Cooper, Steven "General_101" Garcia, num0005, Conscars, Zeddikins, John "Ludus", Sean T, Neo Te Aika, killzone64, Crisp, Krevil, and myself.

• Crash Site - An original mission created by Digsite, taking place on the map "Spasm" from the Macworld 1999 showcase. Also features Splash Site, a flooded multiplayer map centered around jet-ski racing.
  
• Early Development Maps - Several prototype maps presented as is for historical purposes.
  
• Earth City (E3 2003 Demo) - The world famous demo, now ported to the retail Halo 2 engine.
  
• Alpha Moon - During development of Halo 2 the Heretic Leader was intended to survive "Alpha Gas Giant" (an earlier iteration of The Arbiter and The Oracle) and flee to the nearby moon, Basis. Players would control the Arbiter as he navigated through the wreckage of the first Halo, with a mix of close quarters stealth and wraith focused vehicle combat.

In 2006 a modding team formed with the goal to create original content for Halo: Custom Edition rather than converting content from other Halo games, known as the Custom Mapping Team (CMT). They disbanded in 2009 while working on Single-Player Version 2 (SPV2), and re-formed in 2011 to attempt a Version 3.
Creative differences arose during the development of SPV3 and a subset of the team instead began to work on The Silent Cartographer: Evolved. The Silent Cartographer was completely remade using custom assets, and the mod was released in 2015. In 2023, TSC:E and related maps from its development were ported to MCC by two of its original developers, Br0nto (aka Siliconmaster) and Ifafudafi (aka Dafi).

• The Silent Cartographer: Evolved - "The Silent Cartographer: Evolved is a ground-up reimagining of the classic Halo level, featuring all-new environments, a finely-tuned gameplay sandbox, and a wide array of well-hidden secrets."
  
• The Truth and Reconciliation: Revisited - "The Truth & Reconciliation: Revisited is a complete audiovisual overhaul of the original Halo level, replicating Halo 1 gameplay with custom, high-fidelity assets."

A group of modders and collaboration projects that aim to deliver high quality assets and experiences. Less of a team and more so a collection of talent and shared resources. Many Digsite members got their start working with VKMT.

• Lumoria: Definitive Edition - Originally created by TM Mapping Team members Higuy and Lodeman, Lumoria is an original story that acts as a standalone singleplayer expansion to Halo: Combat Evolved. Conscars, who had created skyboxes for Lumoria and other mods, collaborated with Higuy to create the Lumoria themed multiplayer map Geomar.
  The Definitive Edition was made by D|S-C0RD (aka Navarone) and Elite (aka Elote) with the blessings of the original creators, and ports both Lumoria and Geomar to MCC, featuring numerous updates and bug fixes. Halo: PC assets have been replaced with their original Xbox counterparts, assets that were originally ported from later Halo titles were replaced with custom made CE styled assets, and fan made recreations of pre-release assets were replaced with their Digsite equivalents.
  
• Canyon - A singleplayer conversion of the custom multiplayer map sniper canyon redux. Created by Elite, the mission features custom NPCs not encountered in Halo: Combat Evolved's campaign. This collection features the version included with CE+, which contains an expanded weapons sandbox. The original mod with stock weapons can be found here.
  
• Closure - coming soon...
  
• Halo 2: Uncut - "Using evidence found within Halo 2's tags, map scripts, and other external media, Halo 2: Uncut aims to accurately restore as much cut content into the game as possible. Features pre-release elements such as cut weapons, cut weapon and vehicle functionalities, restored cut encounters and map scripts, and features Director's Cut-style cutscenes."

• Original Xbox Maps - When Halo: Combat Evolved was ported to PC some maps received alterations to their design, collision, and layouts. Thanks to the efforts of Aerocatia the original Xbox maps are now playable in MCC for those who prefer them.
  
• Neutral Host Edition - Formerly known as Halo 1: Final, NHE is a modification for the original Xbox that aimed to be the most competitively viable way to play Halo: Combat Evolved over LAN. The original Halo 1: Final mod featured an in-game talking timer and removed several sound effects for clarity. NHE introduced scripts allowing for an additional Xbox to act as a pseudo-dedicated server to remove host advantage, and removed weapon spread. Both mods featured original maps created by insidi0us, PwNyTar, dds, stunt_man, hirsute, and Hasuku. The maps without gameplay changes were ported to MCC by dds, stunt_man, and DSalimander.
  
• Pro Edition - Formerly known as Patch Edition, Pro Edition is an evolution of NHE that includes competitive changes to the stock Halo: Combat Evolved maps. While I do not prefer them, the entire collection of Xbox, NHE, and Pro maps can be found here for the complete competitive Xbox experience.
  
• Halo 1.5 - Evolved from the Halo+ mod for Xbox, Halo 1.5 is the predecessor to Halo 1: Final/Neutral Host Edition. It featured two maps that were not included in later mods, Crossway by dds and Levee by insidi0us. Both maps along with other competitive maps by stunt_man, DSalimander, il Duce Primo, and Spiral were ported to MCC by Slatchey and Split_CE apart of the Guide Map Pack.

• Social Map Pack - Competitive Custom Edition maps featuring buffed shotguns and needlers courtesy of VKMT. This collection of ports was created by Slatchey and Split_CE.

• Popetacular Map Pack - A collection of maps created by PopeTX28, ported to MCC by Split_CE.
  
• CE+ - CE+ (and its expansion Beyond) is a reinvention of Halo's weapon sandbox while maintaining the balance and feel of Combat Evolved.
  
• Halo 3 Maps - killzone64, ShmeeGrim, and Neckzilla represent some of the greatest Halo 3 map makers in the modding community.

Blake Hodges (aka "Delta 905" or "Delta Rampancy") is a developer who worked at 343 Industries and has created a few Halo 2 multiplayer maps.

• Chiron Station - One of the first MCC Workshop mods, it even has its files officially included in the Halo 2 Editing Kit.
  
• Rampancy Map Pack - "3 Multiplayer Maps in honor of Halo 2's 20th Birthday!"