I didn't see these anywhere after searching the forums and the wiki, so I just wrote a little plugin to get them.
These are the indexes and names of all the user messages in TF2 (as of this post).
PHP Code:
Index: 0, Name: Geiger
Index: 1, Name: Train
Index: 2, Name: HudText
Index: 3, Name: SayText
Index: 4, Name: SayText2
Index: 5, Name: TextMsg
Index: 6, Name: ResetHUD
Index: 7, Name: GameTitle
Index: 8, Name: ItemPickup
Index: 9, Name: ShowMenu
Index: 10, Name: Shake
Index: 11, Name: Fade
Index: 12, Name: VGUIMenu
Index: 13, Name: Rumble
Index: 14, Name: CloseCaption
Index: 15, Name: SendAudio
Index: 16, Name: VoiceMask
Index: 17, Name: RequestState
Index: 18, Name: Damage
Index: 19, Name: HintText
Index: 20, Name: KeyHintText
Index: 21, Name: HudMsg
Index: 22, Name: AmmoDenied
Index: 23, Name: AchievementEvent
Index: 24, Name: UpdateRadar
Index: 25, Name: VoiceSubtitle
Index: 26, Name: HudNotify
Index: 27, Name: HudNotifyCustom
Index: 28, Name: PlayerStatsUpdate
Index: 29, Name: PlayerIgnited
Index: 30, Name: PlayerIgnitedInv
Index: 31, Name: HudArenaNotify
Index: 32, Name: UpdateAchievement
Index: 33, Name: TrainingMsg
Index: 34, Name: TrainingObjective
Index: 35, Name: DamageDodged
Index: 36, Name: PlayerJarated
Index: 37, Name: PlayerExtinguished
Index: 38, Name: PlayerJaratedFade
Index: 39, Name: PlayerShieldBlocked
Index: 40, Name: BreakModel
Index: 41, Name: CheapBreakModel
Index: 42, Name: BreakModel_Pumpkin
Index: 43, Name: BreakModelRocketDud
Index: 44, Name: CallVoteFailed
Index: 45, Name: VoteStart
Index: 46, Name: VotePass
Index: 47, Name: VoteFailed
Index: 48, Name: VoteSetup
Index: 49, Name: PlayerBonusPoints
Index: 50, Name: SpawnFlyingBird
Index: 51, Name: PlayerGodRayEffect
Index: 52, Name: SPHapWeapEvent
Index: 53, Name: HapDmg
Index: 54, Name: HapPunch
Index: 55, Name: HapSetDrag
Index: 56, Name: HapSetConst
Index: 57, Name: HapMeleeContact
I figured these would be useful to some people.