Too many to count...
-1921, 22, 23-24 Exhibits
-E120
-V100
-1934, 35-36, and other Diamond Matchbooks
-V122
-N172 (this one about 3-4 times)
-etc.
Sometimes I think a set would be right up my alley only to find out when I'm half-way there or so that it just doesn't do it for me. The N172's are just cost prohibitive more than anything else-- if I didn't have a wife, kids, and my $240K Student Loan debt I'd probably pursue them more vehemently