some statistics:

The films I haven't seen from the revised AFI list:

98. Yankee Doodle Dandy (1942)
95. The Last Picture Show (1971)
92. Goodfellas (1990)
91. Sophies Choice (1982)
90. Swing Time (1936)
87. 12 Angry Men (1957)
82. Sunrise (1927)
80. The Apartment (1960)
79. The Wild Bunch (1969)
77. All the Presidents Men (1976)
75. In the Heat of the Night (1967)
73. Butch Cassidy and the Sundance Kid (1969)
64. Network (1976)
63. Cabaret (1972)
62. American Graffiti (1973)
61. Sullivans Travels (1941)
59. Nashville (1975)
54. M*A*S*H* (1970)
51. West Side Story (1961)
45. Shane (1953)
43. Midnight Cowboy (1969)
40. The Sound of Music (1965)
37. The Best Years of Our Lives (1946)
29. Double Indemnity (1944)
26. Mr. Smith Goes to Washington (1939)
25. To Kill a Mockingbird (1962)

from the remaining 74 films aproximately 35 could make it onto mine (I'd need a lot of rewatches, though), meaning that I consider the list overall good in its selection (although far too conservative).

I have seen less from wpqx's list (only 48 ) , but approximately 25 of them could be on mine. And it's more eclectic.

Nevertheless what it probably all boils down to is that I have to see more American films!
Guess that's what lists are also about.