The Hardy Boys (original series) (1927–1979)

_x_ 1. The Tower Treasure
_x_ 2. The House on the Cliff
_x_ 3. The Secret of the Old Mill
_x_ 4. The Missing Chums
_x_ 5. Hunting for Hidden Gold
_x_ 6. The Shore Road Mystery
_x_ 7. The Secret of the Caves
_x_ 8. The Mystery of Cabin Island
_x_ 9. The Great Airport Mystery
_x_ 10. What Happened at Midnight
_x_ 11. While the Clock Ticked
_x_ 12. Footprints under the Window
_x_ 13. The Mark on the Door
_x_ 14. The Hidden Harbor Mystery
_x_ 15. The Sinister Sign Post
___ 16. A Figure in Hiding
___ 17. The Secret Warning
_x_ 18. The Twisted Claw
_x_ 19. The Disappearing Floor
___ 20. Mystery of the Flying Express
_x_ 21. The Clue of the Broken Blade
_x_ 22. The Flickering Torch Mystery
_x_ 23. The Melted Coins
_x_ 24. The Short-Wave Mystery
_x_ 25. The Secret Panel
_x_ 26. The Phantom Freighter
___ 27. The Secret of Skull Mountain
_x_ 28. The Sign of the Crooked Arrow
_x_ 29. The Secret of the Lost Tunnel
___ 30. The Wailing Siren Mystery
_x_ 31. The Secret of Wildcat Swamp
___ 32. The Crisscross Shadow
_x_ 33. The Yellow Feather Mystery
_x_ 34. The Hooded Hawk Mystery
___ 35. The Clue in the Embers
_x_ 36. The Secret of Pirates' Hill
_x_ 37. The Ghost at Skeleton Rock
_x_ 38. Mystery at Devil's Paw
_x_ 39. The Mystery of the Chinese Junk
_x_ 40. Mystery of the Desert Giant
_x_ 41. The Clue of the Screeching Owl
_x_ 42. The Viking Symbol Mystery
_x_ 43. The Mystery of the Aztec Warrior
_x_ 44. The Haunted Fort
_x_ 45. The Mystery of the Spiral Bridge
_x_ 46. The Secret Agent on Flight 101
_x_ 47. Mystery of the Whale Tattoo
_x_ 48. The Arctic Patrol Mystery
_x_ 49. The Bombay Boomerang
_x_ 50. Danger on Vampire Trail
_x_ 51. The Masked Monkey
_x_ 52. The Shattered Helmet
_x_ 53. The Clue of the Hissing Serpent
_x_ 54. The Mysterious Caravan
_x_ 55. The Witchmaster's Key
_x_ 56. The Jungle Pyramid
_x_ 57. The Firebird Rocket
_x_ 58. The Sting of the Scorpion

The Hardy Boys ("digests") (1979–2005)

_x_ 59. Night of the Werewolf
___ 60. Mystery of the Samurai Sword
_x_ 61. The Pentagon Spy
___ 62. The Apeman's Secret
___ 63. The Mummy Case
_x_ 64. Mystery of Smugglers Cove
___ 65. The Stone Idol
___ 66. The Vanishing Thieves
___ 67. The Outlaw's Silver
___ 68. Submarine Caper / Deadly Chase
___ 69. The Four-Headed Dragon
___ 70. The Infinity Clue
_x_ 71. Track of the Zombie
___ 72. The Voodoo Plot
___ 73. The Billion Dollar Ransom
___ 74. Tic-Tac-Terror
___ 75. Trapped At Sea
___ 76. Game Plan for Disaster
___ 77. The Crimson Flame
___ 78. Cave-In!
_x_ 79. Sky Sabotage
_x_ 80. The Roaring River Mystery
___ 81. The Demon's Den
_x_ 82. The Blackwing Puzzle
___ 83. The Swamp Monster
___ 84. Revenge of the Desert Phantom
___ 85. The Skyfire Puzzle
___ 86. The Mystery of the Silver Star
___ 87. Program for Destruction
_x_ 88. Tricky Business
___ 89. The Sky Blue Frame
___ 90. Danger on the Diamond
_x_ 91. Shield Of Fear
___ 92. The Shadow Killers
___ 93. The Serpent's Tooth Mystery
___ 94. Breakdown in Axeblade
_x_ 95. Danger on the Air
___ 96. Wipeout
___ 97. Cast of Criminals
___ 98. Spark of Suspicion
___ 99. Dungeon of Doom
_x_ 100. The Secret of the Island Treasure
_x_ 101. The Money Hunt
___ 102. Terminal Shock
___ 103. The Million-Dollar Nightmare
_x_ 104. Tricks of the Trade
_x_ 105. The Smoke Screen Mystery
___ 106. Attack of the Video Villains
_x_ 107. Panic on Gull Island
___ 108. Fear on Wheels
___ 109. The Prime-Time Crime
___ 110. The Secret of Sigma Seven
___ 111. Three-Ring Terror
___ 112. The Demolition Mission
___ 113. Radical Moves
___ 114. The Case of the Counterfeit Criminals
___ 115. Sabotage at Sports City
___ 116. Rock 'N' Roll Renegades
___ 117. The Baseball Card Conspiracy
___ 118. Danger in the Fourth Dimension
___ 119. Trouble at Coyote Canyon
___ 120. The Case of the Cosmic Kidnapping
___ 121. The Mystery in the Old Mine
___ 122. Carnival of Crime
___ 123. The Robot's Revenge
___ 124. Mystery With a Dangerous Beat
___ 125. Mystery on Makatunk Island
___ 126. Racing to Disaster
___ 127. Reel Thrills
___ 128. Day of the Dinosaur
___ 129. The Treasure at Dolphin Bay
___ 130. Sidetracked to Danger
___ 131. Crusade of the Flaming Sword
___ 132. Maximum Challenge
___ 133. Crime in the Kennel
___ 134. Cross-Country Crime
___ 135. The Hypersonic Secret
___ 136. The Cold Cash Caper
___ 137. High-Speed Showdown
___ 138. The Alaskan Adventure
___ 139. The Search for the Snow Leopard
___ 140. Slam Dunk Sabotage
___ 141. The Desert Thieves
___ 142. Lost in Gator Swamp
___ 143. The Giant Rat of Sumatra
___ 144. The Secret of Skeleton Reef
___ 145. Terror at High Tide
___ 146. The Mark of the Blue Tattoo
___ 147. Trial and Terror
___ 148. The Ice-Cold Case
___ 149. The Chase for the Mystery Twister
___ 150. The Crisscross Crime
___ 151. The Rocky Road to Revenge
___ 152. Danger in the Extreme
___ 153. Eye On Crime
___ 154. The Caribbean Cruise Caper
___ 155. The Hunt for the Four Brothers
___ 156. A Will To Survive
___ 157. The Lure of the Italian Treasure
_x_ 158. The London Deception
___ 159. Daredevils
_x_ 160. A Game Called Chaos
___ 161. Training for Trouble
_x_ 162. The End of the Trail
___ 163. The Spy That Never Lies
___ 164. Skin & Bones
___ 165. Crime in the Cards
___ 166. Past and Present Danger
_x_ 167. Trouble Times Two
___ 168. The Castle Conundrum
___ 169. Ghost of a Chance
___ 170. Kickoff To Danger
_x_ 171. The Test Case
___ 172. Trouble in Warp Space
_x_ 173. Speed Times Five
___ 174. Hide and Sneak
___ 175. Trick-or-Trouble
_x_ 176. In Plane Sight
___ 177. The Case of the Psychic's Vision
_x_ 178. The Mystery of the Black Rhino
_x_ 179. Passport to Danger
___ 180. Typhoon Island
___ 181. Double Jeopardy
_x_ 182. The Secret of the Soldier's Gold
_x_ 183. Warehouse Rumble
_x_ 184. The Dangerous Transmission
___ 185. Wreck and Roll
___ 186. Hidden Mountain
_x_ 187. No Way Out
_x_ 188. Farming Fear
_x_ 189. One False Step
_x_ 190. Motocross Madness

The Hardy Boys Casefiles (1987–1998)

1. Dead on Target
2. Evil, Inc.
3. Cult of Crime
4. The Lazarus Plot
5. Edge of Destruction
6. The Crowning Terror
7. Deathgame
8. See No Evil
9. The Genius Thieves
10. Hostages of Hate
11. Brother against Brother
12. Perfect Getaway
13. The Borgia Dagger
14. Too Many Traitors
15. Blood Relations
16. Line of Fire
17. The Number File
18. A Killing in the Market
19. Nightmare in Angel City
20. Witness to Murder
21. Street Spies
22. Double Exposure
23. Disaster for Hire
24. Scene of the Crime
25. The Borderline Case
26. Trouble in the Pipeline
27. Nowhere to Run
28. Countdown to Terror
29. Thick as Thieves
30. The Deadliest Dare
31. Without a Trace
32. Blood Money
33. Collision Course
34. Final Cut
35. The Dead Season
36. Running on Empty
37. Danger Zone
38. Diplomatic Deceit
39. Flesh and Blood
40. Fright Wave
41. Highway Robbery
42. The Last Laugh
43. Strategic Moves
44. Castle Fear
45. In Self-Defense
46. Foul Play
47. Flight Into Danger
48. Rock 'n' Revenge
49. Dirty Deeds
50. Power Play
51. Choke Hold
52. Uncivil War
53. Web of Horror
54. Deep Trouble
55. Beyond the Law
56. Height of Danger
57. Terror on Track
58. Spiked!
59. Open Season
60. Deadfall
61. Grave Danger
62. Final Gambit
63. Cold Sweat
64. Endangered Species
65. No Mercy
66. The Phoenix Equation
67. Lethal Cargo
68. Rough Riding
69. Mayhem in Motion
70. Rigged for Revenge
71. Real Horror
72. Screamers
73. Bad Rap
74. Road Pirates
75. No Way Out
76. Tagged for Terror
77. Survival Run
78. The Pacific Conspiracy
79. Danger Unlimited
80. Dead of Night
81. Sheer Terror
82. Poisoned Paradise
83. Toxic Revenge
84. False Alarm
85. Winner Take All
86. Virtual Villainy
87. Dead Man in Deadwood
88. Inferno of Fear
89. Darkness Falls
90. Deadly Engagement
91. Hot Wheels
92. Sabotage at Sea
93. Mission: Mayhem
94. A Taste for Terror
95. Illegal Procedure
96. Against All Odds
97. Pure Evil
98. Murder by Magic
99. Frame-up
100. True Thriller
101. Peak Of Danger
102. Wrong Side of the Law
103. Campaign of Crime
104. Wild Wheels
105. Law of the Jungle
106. Shock Jock
107. Fast Break
108. Blown Away
109. Moment Of Truth
110. Bad Chemistry
111. Competitive Edge
112. Cliff-Hanger
113. Sky High
114. Clean Sweep
115. Cave Trap
116. Acting Up
117. Blood Sport
118. The Last Leap
119. The Emperor's Shield
120. Survival of the Fittest
121. Absolute Zero
122. River Rats
123. High Wire Act
124. The Viking's Revenge
125. Stress Point
126. Fire in the Sky
127. Dead in the Water

The Hardy Boys are: The Clues Brothers (1997–2000)

___ 1. The Gross Ghost Mystery
___ 2. The Karate Clue
___ 3. First Day, Worst Day
___ 4. Jump-Shot Detectives
___ 5. The Dinosaur Disaster
___ 6. Who Took the Book?
___ 7. The Abracadabra Case
___ 8. The Dog-Gone Detectives
___ 9. The Pumped-Up Pizza Problem
___ 10. The Walking Snowman
___ 11. The Monster in the Lake
___ 12. King for a Day
_x_ 13. Pirates Ahoy!
_x_ 14. All Eyes On First Prize
___ 15. Slip, Slide, and Slap Shot
_x_ 16. The Fish-Faced Mask Of Mystery
_x_ 17. The Bike Race Ruckus

The Hardy Boys: Undercover Brothers (2005-Date)

1. Extreme Danger
2. Running On Fumes
3. Boardwalk Bust
4. Thrill Ride
5. Rocky Road
6. Burned
7. Operation: Survival
8. Top Ten Ways to Die
9. Martial Law
10. Blown Away
11. Hurricane Joe
12. Trouble in Paradise
13. The Mummy's Curse
14. Hazed
15. Death And Diamonds
16. Bayport Buccaneers
17. Murder At The Mall
18. Pushed
19. Foul Play
20. Feeding Frenzy
21. Comic Con Artist
22. Deprivation House