1960-S & 1970-S Pennies

1979 doubled date. I have had quite a bit of luck finding these actually.

And

Oops, sorry. I just realized you are from the US, so my hint was kinda useless. http://www.coppercoins.com looks pretty good though.

Good luck

the ones I look for off the top of my head is
1960 small date,1964 DDR,1968 D/D,1968D DDR
1969S DDO, 1970S DDO,1970 small date, 1971 DDO
1972 DDO ......... the is the link for a condensed version with
pictures on what to look for http://www.lincolncentresource.com/Top50.html
and some have a decent value...the best one is the 1969 S DDO which have sold
for more than 100,000 dollars. so the higher the worth, the hard they are too find.
more like finding a needle in hay field instead of a haystack. Snowman