As both a collector, dealer, and close watcher of coin trends and populations, I'd like to share with you some coins which I notice are severely undervalued in todays market.  These are coins that could easily go up in value if the market for them burgeons even a little.

1. Problem Free Classic Head Half Cents:  Long the little sister to Large Cents, these coins have gone ignored.  But they all have paltry mintages, and it's tough to find them nice and uncleaned.  Look for these to increase by as much as 100 percent in the next 5 years.  Of note, while Braided Hair Half Cents have extremely tiny mintages, they were saved in enough numbers and are more easily found in upper grades.

2.  Two Cent Pieces in Unciculated RED or RED/BROWN.  These just are not out there in the market place.  Search ebay for even the common 1864 or 1865 in MS 63 R or R/B and good luck finding even one example, be it nice or not.  These are well under 500 dollars and an exceptional value.  Look for them to rise as interest in early Lincoln copper rises (it already has).

3.  Key Date Three Cent Nickels.  Any Three Cent Nickel with a mintage of under 100,000 in mid grade is a great value.  They are cheap because there is no currently alot of interest in the series.  But if interest ever picked up, these coins could easily top 1,000 dollars a piece.

4.  Seated Half Dimes in general.  Do some research and learn the series.  There are TONS of dates that just are not out there, for any price.  For example, dates in low grades, at under 100 dollars that you might not even find at a large show: 1853 No Arrows, 1852 O, all the 60's S mints.  When you learn the series you will recognize the 15-20 very common dates.  The rest are TOUGH.  And if you can find them nice, BUT THEM.  Did the dealer over price or over grade it? BUY IT ANYWAY.  Dates I recommend: Anything 1863 to 1869, 1839 O, 1840 O No Drapery, 1842, 1842 O, 1844, 1844 O, 1848 Large Date, 1871 S.  The 1837's, while a beautiful design, are overvalued as type coins.

5.  Problem Free Bust Dimes.  I can't find any....can you?

6.  Semi-Key Mercury Dimes.  These are already on the rise, and the Coin Trends magazines are having a hard time catching up.  Any Semi-Key (even some in the 30's such as 35-D are very hard in solid VF problem free original).  Premiums being paid on ebay are HUGE!  The 1921 and 1921 D are actually not that hard.  But try finding nice 1917 D's or 1924 S's.

7.  1875 P or 1876 P Twenty Cent Piece.  Very low mintage pieces.  The Carson City gets all the money, just because of the CC appeal.  But the two Philly dates are rare and underpriced.  Sure to go up.  They stay low now because they are only collected as type coins mainly, so people go for the 1875 S.

8.  Problem Free Bust Quarters before the price jump.  Especially the older large size are very tough to find.  Get them in problem free Fine which is half the price of the Very Fines.  Very hard coins to find.  Good luck on a set.

9.  Seated Liberty Half Dollars that are not super common.  If you follow the Seated Half series for awhile you learn that there are a handful of very common pieces, such as 1854, 1854 O, 1858 O, et al.  But so many are not common, and yet, the price difference in the guide is almost nil.  It's such a huge series that people just can't put together sets, but there is some real satisfaction in having a coin that you may only see once or twice a year on ebay, yet only cost you 20 dollars more than a common date.

10.  Any Barber coins in Problem Free VF.  These coins stayed in circulation forever, so most are AG and G.  Even common dates are tough in nice VF.  Buy any you see.  Some Barber Dimes in VF are still under 10 dollars!  Buy those up for sure.

11.  2007 Proof and Mint Sets.  14 coins in the proof sets.  First Presidential Dollars and the state quarters.  Can you go wrong?  The mint set has almost 14 dollar face value.  I don't think that will be going down in value any time soon. 

12.  Love Tokens.  Every piece is unique, so it's hard for people to put together sets.  But for 10-50 dollars you can get unique beautiful works of art on original US and Foreign coins.  Just search Exonumia>Love Tokens and have a look around.  They are some of my favorite things in the world.

Well, there are 12 Undervalued coins/series.  There are more, but I hope that helps.  Please rate this guide if it was helpful to you.