This is a list of ID's for obtainable and non-obtainable titles in wow for hearthstone/aspire based servers using the command .title add <title ID> (i do not know if the commands/ID's are the same for other servers).
1. Alliance PVP Titles
Private - 1
Corporal - 2
Sergeant - 3
Master Sergeant - 4
Sergeant Major - 5
Knight -6
Knight-Lieutenant - 7
Knight-Captain - 8
Knight-Champion - 9
Lieutenant Commander - 10
Commander - 11
Marshal - 12
Field Marshal - 13
Grand Marshal - 14
2. Horde PVP Titles
Scout - 15
Grunt - 16
Sergeant - 17
Senior Sergeant - 18
First Sergeant - 19
Stone Guard - 20
Blood Guard - 21
Legionnaire - 22
Centurion - 23
Champion - 24
Lieutenant General - 25
General - 26
Warlord - 27
High Warlord - 28
3. Arena Titles
Challenger - 32
Rival - 31
Duelist - 30
Gladiator - 29
Merciless Gladiator - 37
Vengeful Gladiator - 40
Brutal Gladiator - 49
Deadly Gladiator - 56
the Flawless Victor - 96
Arena Master - 50
4. General PVP Titles
of the Alliance - 94
of the Horde - 95
5. General Dungeon/Raid Titles
Champion of the Frozen Wastes - 97
of the Nightfall - 107
Twilight Vanquisher - 89
the Undying - 109
the Immortal - 108
Jenkins - 110
6. Server First kill/quest completion titles
Scarab Lord - 33
Champion of the Naaru - 36
Hand of A'dal - 39
the Magic Seeker - 88
Conqueror of Naxxramas - 90
Obsidian Slayer - 106
7. Reputation Titles
Conqueror - 34
Justicar - 35
of the Shattered Sun - 38
the Diplomat - 48
of the Ebon Blade - 60
Ambassador - 98
the Argent Champion - 99
Guardian of Cenarius - 100
Bloodsail Admiral - 111
8. Holiday Titles
Brewmaster - 41
Elder - 43
Flame Warden - 44
Flame Keeper - 45
the Hallowed - 92
Brewmaster - 101
Merrymaker - 102
the Love Fool - 103
Matron - 104
Patron - 105
9. Milestone Titles
the Seeker - 42
the Exalted - 46
the Explorer - 47
Loremaster - 93
10. Profession Titles
Salty - 51
Chef - 52
Iron Chef - 66
Doctor - 69
Grand Master Alchemist - 64
Grand Master Blacksmith - 65
Grand Master Enchanter - 67
Grand Master Engineer - 68
Grand Master Angler - 70
Grand Master Herbalist - 71
Grand Master Scribe - 72
Grand Master Jewelcrafter - 73
Grand Master Leatherworker - 74
Grand Master Miner - 75
Grand Master Skinner - 76
Grand Master Tailor - 77
11. Unobtainable Titles
the Supreme - 53
of the Ten Storms - 54
of the Emerald Dream - 55
of Quel'Thalas - 78
of Argus - 79
of Khaz Modan - 80
Prophet - 57
the Malefic - 58
Stalker - 59
the Lion Hearted - 82
Champion of Elune - 83
Hero of Orgrimmar - 84
Plainsrunner - 85
of the Darkspear - 86
of the Forsaken - 87
Hero of Northrend - 91
12. Realm first Class Titles
Archmage - 61
Warbringer - 62
Assassin - 63
13. Argent Tournament Titles
of Gnomeregan - 81