The BBC, for better or worse, appears to be releasing Doctor Who serials on DVD with minimal regard for actual fan demand.
Or at least, that was my thesis statement before I did the math. Although they do seem to make some mind-boggling choices of titles to release (really, folks, Timelash? Twin Dilemma? Web Planet?), they do lean toward the more well-regarded titles.
Dividing the 136 classic-era serials that are releasable (i.e. complete, or at least half complete) into quadrants (in order of fan popularity)...
Quad 1 (Most popular): 26 out of 34 currently released, with another 2 in the pipeline
Quad 2 (More popular): 18 out of 34, with 1 more in the pipeline
Quad 3 (Less popular): 14 out of 34, with 3 in the pipeline
Quad 4 (Least popular): 9 out of 34, with 4 in the pipeline
I think my impatience about the remaining top-rank serials stems from, well, the fact that the cast is getting old, and time is taking its toll. The first three Doctors are gone, as are four companions and the two principal actors to play the Master. The survivng iconic lead actors and writers are hitting their 70's and 80's. I look forward to hearing Tom Baker, Nic Courtney, Terrence Dicks, Frazer Hines, et al lending their commentary to further serials before they transcend this celestial plane.
Here are the 67 remaining serials, in order of popularity. An asterisk indicates that a release is in the pipeline. The ones I shaded in red are the ten I particularly want to see released as soon as possible.
1. The Deadly Assassin
2. The Seeds of Doom
3. The War Games
4. Terror of the Zygons
5. Warriors' Gate *
6. State of Decay *
7. The Dæmons
8. Terror of the Autons (requires fresh re-colorization)
9. The Ice Warriors (requires reconstruction/animation of missing episodes 2 & 3)
11. The Curse of Peladon 12. The Masque of Mandragora 13. Enlightenment 14. The Tenth Planet (requires reconstruction/animation of missing episode 4) 15. The Face of Evil 16. Frontios 17. Day of the Daleks 18. The Mind of Evil (requires colorization) 19. Snakedance 20. Full Circle * 21. The Ambassadors of Death (requires fresh re-colorization) 22. Mawdryn Undead 23. Frontier In Space 24. Image of the Fendahl 25. Planet of the Spiders 26. Planet of Fire 27. The Sunmakers 28. The Romans * 29. The Greatest Show in the Galaxy 30. The Awakening 31. The War Machines * 32. Death to the Daleks 33. Invasion of the Dinosaurs (requires colorization of episode 1) 34. The Android Invasion 35. Attack of the Cybermen * 36. Revenge of the Cybermen 37. Planet of the Daleks (would require colorization of episode 3) 38. Terminus 39. The Ark 40. Nightmare of Eden 41. The Happiness Patrol 42. The Keys of Marinus 43. The Rescue * 44. Battlefield * 45. Colony in Space 46. The Krotons 47. Four to Doomsday * 48. Meglos 49. The Creature from the Pit 50. The Monster of Peladon 51. The Mutants 52. The Chase 53. Planet of Giants 54. Dragonfire 55. The King's Demons 56. The Time Monster 57. The Horns of Nimon
58. The Silver Nemesis
59. The Gunfighters
60. The Sensorites
61. The Space Musuem
62. Paradise Towers
63. The Dominators
64. Delta and the Bannermen
66. Time and the Rani
67. The Twin Dilemma *
(fan popularity is determined by an 11 Oct 08 visit to the Dynamic Rankings website)