Nagrand Slam

Lantresor chain:
1. Do My Eyes Deceive Me
2. Not On My Watch!
3. Mo'mor the Breaker
4. The Ruins of Burning Blade
5. The Twin Clefts of Nagrand
6. Diplomatic Measures
7. Armaments for Deception
8. Ruthless Cunning
9. Returning the Favor
10. Body of Evidence
11. Message to Telaar

Corki:
12. HELP!
13. Corki's Gone Missing Again!
14. Corki's Ransom
15. Cho'war the Pillager

Other Telaar quests:

16. Solving the Problem
17. Stopping the Spread
18. The Ravaged Caravan
19. Fierce Enemies

Ring of Blood:
20. The Ring of Blood: Brokentoe
21. The Ring of Blood: The Blue Brothers
22. The Ring of Blood: Rokdar the Sunderer
23. The Ring of Blood: Skra'gath
24. The Ring of Blood: The Warmaul Champion
25. The Ring of Blood: The Final Challenge

Nesingwary chain:
26. The Nesingwary Safari
27. Clefthoof Mastery
28. Clefthoof Mastery
29. Clefthoof Mastery
30. Talbuk Mastery
31. Talbuk Mastery
32. Talbuk Mastery
33. Windroc Mastery
34. Windroc Mastery
35. Windroc Mastery
36. The Ultimate Bloodsport

37. I'm Saved!: occurs randomly near Nesingwary's camp.

38. I Must Have Them!
39. Bring Me The Egg!

40. Murkblood Invaders: drop from wandering Murkblood Invaders.
41. Ortor My Old Friend...

42. The Totem of Kar'dash
43. Wanted: Giselda the Crone
44. Wanted: Zorbo the Advisor
45. Wanted: Durn the Hungerer

Throne of the Elements:
46. The Throne of the Elements
47. The Howling Wind: random drop from Nagrand air elementals.
48. Murkblood Corrupters
49. A Rare Bean
50. Agitated Spirits of Skysong
51. Blessing of Incineratus
52. The Spirit Polluted
53. The Underneath
54. The Tortured Earth
55. Eating Damnation
56. Shattering the Veil
57. Gurok the Usurper
58. Muck Diving

Altruis:
59. He Called Himself Altruis...
60. Survey the Land
61. Buying Time
62. The Master Planner
after 3 Terokkar quests, which do not count.
63. Forge Camp: Annihilated

64. Altruis / Altruis: from Aldor/Scryers in Shadowmoon Valley.
65. Against the Legion
66. Against the Illidari
67. Against All Odds
68. Illidan's Pupil

Aeris Landing:
69. The Consortium Needs You!
70. A Head Full of Ivory: only available at Neutral.
71. Stealing from Thieves: only available at Neutral.
72. Obsidian Warbeads: first turnin.
73. Gava'xi
74. Matters of Security
75. Membership Benefits (counts once, not monthly)

76. The Master's Grand Design?
77. Vision of the Dead

78. Oshu'gun Crystal Powder

79. Visions of Destruction
80. A Mystifying Vision

Let me know if there are still any missing quests.

Wowhead lists the following quests in the Nagrand category:

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• 62 quests available to both factions
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• 30 Alliance-only quests
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• 44 Horde-only quests
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However:

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• 2 quests are mutually exclusive Aldor/Scryer (Altruis/Altruis)
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• 2 quests are available only if you're below Friendly with Consortium (A Head Full of Ivory,Stealing from Thieves)
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• 4 quests are reputation-exclusive with Consortium (membership benefits) and are monthly (but apparently do satisfy the achievement, at least once)
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• 6 quests (for each faction) are daily or repeatable and don't count:
  
  • 
    
  • Alliance: More Warbeads (Kurenai), In Defense of Halaa, Oshu'gun Crystal Powder*
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  • Horde: More Warbeads (Mag'har), Enemies, Old and New, Oshu'gun Crystal Powder*
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  • Both: More Crystal Fragments, More Heads Full of Ivory, More Obsidian Warbeads
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  *note that both flavors of Oshu'gun Crystal Powder have a first-time quest, which does give credit, and a follow-up quest, which does not, listed separately on Wowhead
  
• 
  
  
• 3 quests (for each faction) are optional 'breadcrumbs' quests and not available if you've already done the follow-up (and it's not clear whether they would count anyway)
  
  • 
    
  • Alliance: The Nesingwary Safari, A Mystifying Vision, Visions of Destruction
  • 
    
  • Horde: The Nesingwary Safari, A Strange Vision, Kroghan's Report
  • 
    
  
  
• 
  

Which leaves, by my count, 76 quests for Alliance and 90 for Horde, not counting the Consortium sub-Friendly quests, breadcrumbs, or monthly quests. Not sure if there really are 1-3 extra quests beyond those required for the achievement, or if there are a couple that look like they should count but do not.

Here is a list of common quests you should have completed:
- Telaar
- Altruis the Sufferer (from Telaar & later on via Aldor / Scryers)
- Throne of Elements
- Wazat (Jump-o-Tron)
- Auchindoun (Master's Grand Design, etc)
- Ring of Blood
- Lantresor of the Burning Blade (via Telaar)
- Aeris Landing
- Nesingwary's Camp (including saving Kristen)
- Halaa
- Captive Escort
- Corki

Here are a few uncommon ones:
- Howling Wind
- Murkblood Invasion Plans
- I'm saved!

Good luck!