One of many "best liked" Polls from the Ultimate GTO Site (this one from 05) showing a 1000 polled results.
Dozens of polls....looks close on a few like 69 and 70.
http://ultimategto.com/cgi-bin/pollp...eek=52&year=05
Poll Question #20 (from 2005): Which year of GTO is your favorite?
1000 responses collected
1964 6%
1965 13%
1966 11%
1967 20%
1968 9%
1969 19%
1970 13%
1971 3%
1972 2%
1973 1%
1974 1%
2004 3%
2005 0%