The first thing that comes to mind when I think of the 1966 Topps set is 5-cent wax packs. Even though 5-cent wax packs were available way before 1966, it was the cheapest pack you could buy that year, since 1-cent wax packs were discontinued after 1965.
The second thing that comes to mind when I think of the 1966 Topps set is really expensive high-number cards from the 7th series (#523-598). Being about only 50 cards short from completing this set, it just seems impossible sometimes to find cards from the final series reasonably priced according to book values. The only other Topps baseball card set that seems to come close in premium pricing for high-number cards is the 1967 Topps set, which is actually really close. The 1968-1969 Topps high number cards are relatively simple to find, while 1970-1972 Topps (although very difficult to find) don't even come close to the rarity of 1966-1967 Topps.
The third thing that comes to mind when I think about the 1966 Topps set is, well, the 1988 Topps set. The 1988 Topps set always reminded me of a cross between the 1966 and 1967 Topps sets. Actually, it wasn't until I made this connection that I really started to appreciate the 1988 Topps set.
What things come to mind when you remember the 1966 Topps baseball card set?