madmax

Once on the mega site right-click and download the patch you need.
Download page contains:
WoW-1.9.0-deDE-patch.exe WoW-1.9.0-enGB-patch.exe WoW-1.9.0-enUS-patch.exe WoW-1.9.0-frFR-patch.exe

Before the Storm - 1.12.x to 2.0.1
Once on the mega site just right-click and download the patches you need
This patch allows you to upgrade from Classic to The Burning Crusade, useful if you dont have expansion disks.
deDE
WoW-Before-the-Storm-deDE-patch.zip
enGB
WoW-Before-the-Storm-enGB-patch.zip
enUS
WoW-Before-the-Storm-enUS-patch.zip
frFR
WoW-Before-the-Storm-frFR-patch.zip
Important Notes (Please read and understand before downloading)
With this patch you can patch Classic into The Burning Crusade. However, Please note that if you have a Burning Crusade install disk you should use it after applying this patch to add The Burning Crusade content to your client, then patch as normal.
If you do not use an install disk / ISO and continue to patch as normal, you will be able to access a Mangos Burning Crusade server, BUT you will not have access to Burning Crusade content such as Outlands, nor will you be able to level past 60.
Blizzard had 2 versions of clients during Burning Crusade and Wrath of the Lich King. One was TBC but classic only and the other was full Burning Crusade.
If you do not have an install disk you may search the site for links to torrents or contact MadMax who may be able to direct you.

Mangos One Server - 0.21
For: World of Warcraft: The Burning Crusade
Wiki: https://www.getmangos.eu/wiki/documentation/installation-guides/
Status: Playable
Support client versions: 2.3.4 (8606)
Mangosone-Serverx86.zip (32 Bit)
MangosOne-Serverx64.zip (64 Bit)
Builtin Scripts (SD3 & Eluna) Map Extractors Realm, World & Character databases Authentication Realm-Daemon server (realmd) Mangos-Daemon world server (Mangosd) Requirements:
C++ Redistributable for Visual Studio 2015 (Included in .zip)

Mangos Three Server - 0.21
For: World of Warcraft: Cataclysm
Wiki: https://www.getmangos.eu/wiki/documentation/installation-guides/
Status: Testing, Unstable, Development
Support client versions: 4.3.4 (15595)
MangosThree-Serverx86.zip (32 Bit)
MangosThree-Serverx64.zip (64 Bit)
Builtin Scripts (SD3 & Eluna) Map Extractors Realm, World & Character databases Authentication Realm-Daemon server (realmd) Mangos-Daemon world server (Mangosd) Requirements:
C++ Redistributable for Visual Studio 2015 (Included in .zip)

Mangos Two Server - 0.21
For: World of Warcraft: Wrath of The Lich King
Wiki: https://www.getmangos.eu/wiki/documentation/installation-guides/
Status: Playable
Support client versions: 3.3.5a (12340)
MangosTwo-Serverx86.zip (32 Bit)
MangosTwo-Serverx64.zip (64 Bit)
Builtin Scripts (SD3 & Eluna) Map Extractors Realm, World & Character databases Authentication Realm-Daemon server (realmd) Mangos-Daemon world server (Mangosd) Requirements:
C++ Redistributable for Visual Studio 2015 (Included in .zip)

Mangos Zero Server with playerbots
For: World of Warcraft Classic
Install Guides: https://www.getmangos.eu/wiki/documentation/installation-guides/
Status: Playable
Support client versions: 1.12.1 (build 5875),1.12.2 (build 6005) and 1.12.3 (build 6141)
  MangosZero-Serverx86.zip (32 bit)
MangosZero-Serverx64.zip (64 bit)
Built in Scripts (SD3 & Eluna) Playerbot Allows players to spawn bots to group up and play with them. Settings for this are in aiplayerbot.conf.dist This can be enabled or disabled in the config file Map Extractors Realm, World & Character databases Authentication Realm-Daemon server (realmd) Mangos-Daemon world server (Mangosd) Requirements:
C++ Redistributable for Visual Studio 2015 (Included in .zip)

2.4.2
These patches are for the Mac OSX client.
Patch Notes
Patches 2.0.x to 2.4.2
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.4.2-deDE-patch.zip

These patches are for the Mac OSX client.
Once on the mega site right-click and download the patch you need.
Download page contains:
WoW-2.3.0-koKR-patch.zip

2.3.2
These patches are for the Mac OSX client.
Patch Notes
Patches 2.3.0 to 2.3.2
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.3.0.7561-to-2.3.2.7741-koKR-patch.zip

2.3.3
These patches are for the Mac OSX client.
Patch Notes
Patches 2.3.2 to 2.3.3
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.3.2.7741-to-2.3.3.7799-koKR-patch.zip

2.4.0
These patches are for the Mac OSX client.
Patch Notes
Patches 2.3.3 to 2.4.0
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.3.3.7799-to-2.4.0.8089-koKR-patch.zip

2.4.0  Fury of the Sunwell
These patches are for the Mac OSX client.
Patches 2.0.x to 2.4.0
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.4.0-enGB-patch.zip WoW-2.4.0-enUS-patch.zip WoW-2.4.0-esES-patch.zip WoW-2.4.0-frFR-patch.zip

2.4.1
These patches are for the Mac OSX client.
Patch Notes
Patches 2.4.0 to 2.4.1
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.4.0.8089-to-2.4.1.8125-enGB-patch.zip WoW-2.4.0.8089-to-2.4.1.8125-enUS-patch.zip WoW-2.4.0.8089-to-2.4.1.8125-esES-patch.zip WoW-2.4.0.8089-to-2.4.1.8125-frFR-patch.zip WoW-2.4.0.8089-to-2.4.1.8125-koKR-patch.zip

2.4.3
These patches are for the Mac OSX client.
Patch Notes
Patches 2.4.2 to 2.4.3
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.4.2.8278-to-2.4.3.8606-deDE-patch.zip WoW-2.4.2.8278-to-2.4.3.8606-enGB-patch.zip WoW-2.4.2.8278-to-2.4.3.8606-enUS-patch.zip WoW-2.4.2.8278-to-2.4.3.8606-esES-patch.zip WoW-2.4.2.8278-to-2.4.3.8606-frFR-patch.zip WoW-2.4.2.8278-to-2.4.3.8606-koKR-patch.zip WoW-2.4.2.8278-to-2.4.3.8606-ruRU-patch.zip

These patches are for the Mac OSX client.
Once on the mega site right-click and download the patch you need.
Download page contains:
WoW-1.12.0-deDE-patch.zip WoW-1.12.0-enGB-patch.zip WoW-1.12.0.5595-to-1.12.1.5875-enGB-patch.zip WoW-1.12.0-enUS-patch.zip WoW-1.12.0.5595-to-1.12.1.5875-enUS-patch.zip WoW-1.12.0-frFR-patch.zip

2.0.12
Patch Notes
Patches 2.0.10 to 2.0.12
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.10.6448-to-2.0.12.6546-deDE-patch.exe WoW-2.0.10.6448-to-2.0.12.6546-engb-patch.exe WoW-2.0.10.6448-to-2.0.12.6546-enUS-patch.exe WoW-2.0.10.6448-to-2.0.12.6546-esES-patch.exe WoW-2.0.10.6448-to-2.0.12.6546-frFR-patch.exe koKR Missing

2.0.4 The Black Temple
Patch Notes
Patches 2.0.12 to 2.1.0
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.12.6546-to-2.1.0.6692-koKR-patch.exe WoW-2.0.12.6546-to-2.1.0.6692-deDE-patch.exe WoW-2.0.12.6546-to-2.1.0.6692-engb-patch.exe WoW-2.0.12.6546-to-2.1.0.6692-enUS-patch.exe WoW-2.0.12.6546-to-2.1.0.6692-esES-patch.exe WoW-2.0.12.6546-to-2.1.0.6692-frFR-patch.exe

2.0.3  The Burning Crusade
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.3-engb-patch.exe WoW-2.0.3-enUS-patch.exe WoW-2.0.3-esES-patch.exe WoW-2.0.3-frFR-patch.exe

2.0.10
Patch Notes
Patches 2.0.3 to 2.0.10
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.3.6299-to-2.0.10.6448-deDE-patch.exe WoW-2.0.3.6299-to-2.0.10.6448-enGB-patch.exe WoW-2.0.3.6299-to-2.0.10.6448-enUS-patch.exe WoW-2.0.3.6299-to-2.0.10.6448-esES-patch.exe WoW-2.0.3.6299-to-2.0.10.6448-frFR-patch.exe WoW-2.0.3.6299-to-2.0.10.6448-koKR-patch.exe

2.0.12
Patch Notes
Patches 2.0.3 to 2.0.12
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.3.6299-to-2.0.12.6546-deDE-patch.exe WoW-2.0.3.6299-to-2.0.12.6546-enGB-patch.exe WoW-2.0.3.6299-to-2.0.12.6546-enUS-patch.exe WoW-2.0.3.6299-to-2.0.12.6546-esES-patch.exe WoW-2.0.3.6299-to-2.0.12.6546-frFR-patch.exe WoW-2.0.3.6299-to-2.0.12.6546-koKR-patch.exe

2.0.4
Patch Notes
Patches 2.0.3 to 2.0.4
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.3.6299-to-2.0.4.6314-enUS-patch.zip

2.0.5
Patch Notes
Patches 2.0.3 to 2.0.5
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.3.6299-to-2.0.5.6320-deDE-patch.exe WoW-2.0.3.6299-to-2.0.5.6320-enGB-patch.exe WoW-2.0.3.6299-to-2.0.5.6320-enUS-patch.exe WoW-2.0.3.6299-to-2.0.5.6320-esES-patch.exe WoW-2.0.3.6299-to-2.0.5.6320-frFR-patch.exe

2.0.7
Patch Notes
Patches 2.0.3 to 2.0.7
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.3.6299-to-2.0.7.6383-deDEpatch.exe WoW-2.0.3.6299-to-2.0.7.6383-enGB-patch.exe WoW-2.0.3.6299-to-2.0.7.6383-enUS-patch.exe WoW-2.0.3.6299-to-2.0.7.6383-esES-patch.exe WoW-2.0.3.6299-to-2.0.7.6383-frFR-patch.exe WoW-2.0.3.6299-to-2.0.7.6383-koKR-patch.exe

2.0.5
Patch Notes
Patches 2.0.4 to 2.0.5
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.4.6314-to-2.0.5.6320-enUS-patch.exe Missing: enGB, esES, frFR, koKR, deDE

2.0.6
Patch Notes
Patches 2.0.5 to 2.0.6
Once on the mega site just right-click and download the patches you need
Contains:
WoW-2.0.5.6320-to-2.0.6.6337-deDE-patch.exe WoW-2.0.5.6320-to-2.0.6.6337-enGB-patch.exe WoW-2.0.5.6320-to-2.0.6.6337-enUS-patch.exe WoW-2.0.5.6320-to-2.0.6.6337-esES-patch.exe WoW-2.0.5.6320-to-2.0.6.6337-frFR-patch.exe