OK, out of idle curiosity, I took a look at the tracks on my computer and found the following are the longest tracks I've got.
Let's see how many are longer than anything by Iron Maiden...
Omitted: classical music, live recordings, tracks which contain more than one song, non-musical material.
To shorten the vertical length of this post, only the longest song by each artist is printed full-size; all others are made small.
1. Jethro Tull, "A Passion Play" - 44:58
2. Jethro Tull, "Thick As A Brick" - 43:36
3. Monster Magnet, "Tab 25" - 32:14
4. Symphony X, "The Odyssey" - 24:14
5. Dream Theater, "Octavarium" - 23:59
6. Pink Floyd, "Atom Heart Mother Suite" - 23:37
7. Pink Floyd, "Echoes" - 23:28
8. Spock's Beard, "The Water" - 23:10
9. Dream Theater, "A Change Of Seasons" - 23:08
10. Genesis, "Supper's Ready" - 22:58
11. Fates Warning, "The Ivory Gate Of Dreams" - 21:58
12. Yes, "The Gates Of Delirium" - 21:54
13. Yes, "Ritual" - 21:31
14. Flower Kings, "Monsters & Men" - 21:19
15. Frank Zappa, "The Adventures Of Greggary Peccary" - 20:50
16. Symphony X, "The Divine Wings Of Tragedy" - 20:42
17. Rush, "2112" - 20:37
18. Yes, "The Remembering" - 20:32
19. Yes, "The Revealing Science Of God" - 20:23
20. Rush, "The Fountain Of Lamneth" - 20:00
21. Flower Kings, "Love Supreme" - 19:43
22. Yes, "That, That Is" - 19:15
23. Rhapsody, "Gargoyles, Angels Of Darkness" - 19:02
24. Yes, "Close To The Edge" - 18:46
25. Frank Zappa, "Little House That I Used To Live In" - 18:41
26. Charles Mingus, "Trio And Group Dancers" - 18:38
27. Yes, "Mind Drive" - 18:38
28. Porcupine Tree, "The Sky Moves Sideways, Phase 1" - 18:37
29. Yes, "The Ancient" - 18:32
30. Edguy, "The Kingdom" - 18:23
31. Flower Kings, "Drivers Seat" - 18:20
32. Rush, "Cygnus X-1 Book II" - 18:10
33. Frank Zappa, "N-Lite" - 18:00
34. Frank Zappa, "Big Swifty" - 17:22
35. Pink Floyd, "Dogs" - 17:08
36. Frank Zappa, "The Gumbo Variations" - 16:57
37. Liquid Tension Experiment, "When The Water Breaks" - 16:57
38. Porcupine Tree, "The Sky Moves Sideways, Phase 2" - 16:44
39. Iced Earth, "Dante's Inferno" - 16:29
40. Spock's Beard, "Time Has Come" - 16:22
41. Porcupine Tree, "Moonloop" - 16:17
42. Kansas, "Incomudro: Hymn To The Atman" - 16:10
43. Fates Warning, "Still Remains" - 16:06
44. Spock's Beard, "Flow" - 15:50
45. Tool, "Disgustipated" - 15:47
46. Riverside, "Second Life Syndrome" - 15:40
47. Stars On 45 (1981 single) - 15:34
48. Anglagard, "Hoestsejd" - 15:33
49. Spock's Beard, "The Light" - 15:32
50. Yes, "Awaken" - 15:28
51. Frank Zappa, "Beat The Reaper" - 15:23
52. Ars Nova, "Trust To The Future" - 15:21
53. Funkadelic, "(Not Just) Knee Deep" - 15:21
54. Gamma Ray, "Heading For Tomorrow" - 14:31
55. Dream Theater, "In The Name Of God" - 14:14
56. Porcupine Tree, "Metanoia I: Intermediate Jesus" - 14:14
57. The Tea Party, "Walk With Me" - 14:14
58. Edguy, "Theater Of Salvation" - 14:10
59. Blind Guardian, "And Then There Was Silence" - 14:07
60. Helloween, "The King For 1000 Years" - 13:54
61. Dream Theater, "The Glass Prison" - 13:52
62. Opeth, "By The Pain I See In Others" - 13:50
63. Tool, "Third Eye" - 13:47
64. Dream Theater, "The Great Debate" - 13:45
65. Rhapsody, "Queen Of The Dark Horizons" - 13:44
66. Iron Maiden, "Rime Of The Ancient Mariner" - 13:41
My point?
Ermm...
Hey, look over there, a three-legged dog!