10

Everybody is probably familiar with PSA grading of unopened wax packs. If not, it's done on a scale from 1 (poor) to 10 (Gem Mint) but grades of 10 are incredibly rare. Looking at the PSA Pop report for packs from 1950 to 1979, there have been only 15 non-sport full size wax packs that managed a grade of 10 (although there are a bunch more cello packs with 10s):

1964 Outer Limits x 3

1965 Disneyland x 5

1969 OPC Man on the Moon x 2

1971 OPC Partridge Family x 1

1978 Star Wars series 4 x 2

and 1978 Star Wars series 5 x 2

Recently 2 more packs joined the 10 club - both 1967 Hot Seat Stickers and here are the pictures!

(Click the first one to see PSA grading standards and the second to see the Hot Seat Stickers listing)

If anybody has pictures of the other 10s, please post them.