epends on whether you have enough money to go the rare route or whether your budget only allows you to collect for the fun and interest in the subject. Everyone would love to have the rare 16-D dime or the 09S VDB penny but for my money and the love of the design, I go th ebest condition I can on the more common coins. My favorite is the $2.50 gold coin with the incised indian design. The St Gaudins are beautiful and be collected as current bullion coins if you can't afford $1000 for a double eagle.
The seated liberty coins are beautiful as are the flowing hair cents and half cents. I also have a fondness for inidan head pennies and buffalo nickels.