Halo 1 Disc - 13

Battle Creek

Sidewinder

Damnation

Rat Race

Prisoner

Hang 'Em High

Chill Out

Derelict

Boarding Action

Chiron TL-34

Blood Gulch

Wizard

Longest

Halo 1 PC Disc - 6

Timberland

Death Island

Gephyrophobia

Danger Canyon

Ice Fields

Infinity

Halo 2 Disc - 12

Lockout

Ascension

Midship

Ivory Tower

Beaver Creek

Burial Mounds

Colossus

Zanzibar

Coagulation

Headlong

Waterworks

Foundation

Halo 2 PC Disc - 2

District

Uplift

Halo 2 DLC - 11

Containment

Warlock

Sanctuary

Turf

Desolation

Tombstone

Backwash

Elongation

Gemini

Relic

Terminal

Halo 2 Master Chief Collection - 6

Ascension

Lockout

Zanzibar

?

?

?

Halo 3 Disc - 11

Construct

Epitaph

Guardian

High Ground

Isolation

Last Resort

Narrows

Sandtrap

Snowbound

The Pit

Valhalla

Halo 3 DLC - 10

Foundry

Rat's Nest

Standoff

Avalanche

Blackout

Ghost Town

Cold Storage

Assembly

Orbital

Sandbox

Halo 3 ODST Disc - 3

Citadel

Heretic

Longshore

Halo 4 Disc - 13

Abandon

Adrift

Complex

Exile

Erosion

Haven

Impact

Longbow

Meltdown

Ragnarok

Ravine

Solace

Vortex

Halo 4 DLC - 12

Forge Island

Harvest

Shatter

Wreckage

Landfall

Monolith

Skyline

Daybreak

Outcast

Perdition

Pitfall

Vertigo

By my (possibly incorrect) math, that is 99 total maps.

Now comes the murky, often contradicting quotes about what has made the cut:

Halo Twitter quotes:
"Fun Fact! Halo: The Master Chief Collection has 93 competitive MP maps"
"The only maps *not* included in Halo: TMCC are Halo 2's PDLC Desolation and Tombstone."

IGN stream
Dan Ayoub: "Every map, ever shipped, ever"
Frankie: "With one exception, which is the extra PC maps."

Neogaf quotes from Frankie:
"Yep. Every map, including dlc and even a couple from the pc version."
"There are six PC maps including timberland and gerphyrophobobiarbiarphyrbr."
When asked "Have they said if it includes the the map packs?" Frankie: "Every single map, including the extra pc maps."

Well, there you have it, good luck figuring out what I could not.
profhalo