Cherry Picker's List:
1807 This date comes with Large and Small Stars on the obverse. One variety has 50 punched over 20 on the reverse.
1808 Look for the slightly rarer 1808/7 overdate.
1809 Check the edge lettering on these - some come with irregular ornaments or I's between the words.
1811 Look for the slightly better "Punctuated Date" that has a defect that looks like a period between the 18 and 11 of the date.
1812 Look for the tougher 1812/1 overdates, Large 8 in the date is most rare.
1813 50 C. punched over UNI on the reverse.
1814 Look for the 1814/3 overdate or the engraving mistake which places the E of STATES over an A.
1815 All examples known of this rare date are 1815/2 overdates.
1817 Two overdates are found in this year - 1817/3 (scarce) and 1817/4 (extremely rare and valuable). Look for the 181.7 "punctuated date" variety.
1818 Several varieties including 1818/7 overdates.
1819 Includes some 1819/8 varieties.
1820 Includes 1820/19 overdates. The 2's in the date come with curved or straight bases - the 2's with straight bases come with or without knobs at the top.
1823 Popular varieties include "Broken 3", "Patched 3", and "Ugly 3".
1824 Many of overdates - 1824/1, 1824/4, and 1824.
1827 Look for the 1827/6 overdate. The 2's of this year are found with curved and square bases.
1828 The 2's of this year are found with curved and square bases.
1829 Look for the 1829/7 overdate.
1830 Found with Large and Small 0's in the date.
1836 Look for the blundered 50/00 reverse die. Late in this year, the reverse was modified by replacing the C of the denomination with CENTS and the edge lettering was replaced with reeding.
1839 The "Small Letters" reverse is extremely rare.