AFTER GIFTING US with such lists as the top 50 conservative rock songs, this year National Review offered, under the guidance of political reporter John J. Miller, the "Ten Great Conservative Novels" of the postwar era. Miller is a literature buff whose tastes are more inclusive of pop and genre fiction than were those of such highbrow conservative lit gurus as Irving Babbitt or T.S. Eliot. The novels NR selected, though, were all by reputable novelists, some with known conservative sympathies, some not. Their themes promote such modern conservative ideas as the evils of the Soviets, the counterculture's erosion of proper culture, and the technological destruction of human nature.