I'm jealous of those that mention buying packs in the 50s, 60s, and early 70s...can't even imagine...
For me it was 1978 to 1985...then in 1986 I only bought the complete sets (turned 16...as mentioned earlier...cars, girls, cars, girls...lol) then started right back up in 1987 and by the end of 1990 I was burned out and living on my own...like most here, got back into it 15 years later...
Haven't looked back, although only the last couple years have I bought new packs to hand collate sets...not as fun as when I was a kid, but fun none the less...