Time to fine-tune it a bit.  What about the top 100 words that:

1. Are not proper nouns
2. Are eight letters long
3. None of the letters are the same

Probably more useful.  Here you go:

1. jumprock
2. mazopexy
3. whipjack
4. convexly
5. flipjack
6. jocundly
7. frowzily
8. humpback
9. backflow
10. shivzoku
11. quixotry
12. kevutzah
13. jasponyx
14. cowquake
15. flywinch
16. unmackly
17. jackfish
18. buckwash
19. busywork
20. coltpixy
21. quackery
22. bronzify
23. piquancy
24. squamify
25. muchfold
26. watchful
27. flaxbush
28. wrackful
29. foujdary
30. quantify
31. duckwife
32. overjump
33. wreckful
34. squelchy
35. whiskful
36. chipmunk
37. truckway
38. quotably
39. sulphofy
40. squitchy
41. matchbox
42. methoxyl
43. wrymouth
44. jokingly
45. formazyl
46. kyphotic
47. cityfolk
48. chunkily
49. flyspeck
50. bluejack
51. zwieback
52. buckstay
53. fumingly
54. lampwick
55. ficklety
56. detoxify
57. xylocarp
58. blowzing
59. opaquely
60. chronaxy
61. mynpacht
62. kymbalon
63. xenophya
64. duomachy
65. frumpily
66. boutylka
67. coquetry
68. frozenly
69. onychium
70. backworm
71. furzetop
72. oxyphile
73. wrothful
74. duckwing
75. frowzled
76. trunkway
77. fluework
78. backfold
79. flouncey
80. flapdock
81. octuplex
82. pyknotic
83. knifeway
84. backdown
85. pyknatom
86. playwork
87. humanify
88. azohumic
89. worthful
90. axophyte
91. squawdom
92. unworthy
93. auxocyte
94. smackful
95. frolicky
96. benchful
97. benzylic
98. clothify
99. honeyful
100. vexingly

(My dictionary has some questionable words)