Collecting vs. Investing

We get this question a lot, "What is the best coin to buy?"...Its a good question, but one that is very difficult to answer without first inquiring as to what the objective is of the person asking.  The world of gold and silver coins is huge, and the choices at first glance appear to be almost endless.  First, what kind of money are you thinking of investing?  If that dollar amount is minimal, then silver will most likely be a good choice.  The simple fact that gold is around $1100 per ounce and silver is around $16 per ounce will often times dictate which direction a person chooses.
another consideration is whether a person is buying the coin to collect, or whether they are primarily motivated by the investment potential.  Most investors are going to purchase "bullion" coins which generally have no rare value.  Bullion coins are priced more on the gold or silver content, rather than the intrinsic or numismatic value.  Bullion coins are made in mass quantities.  In addition, date, mint mark and condition(unless really bad) are generally not a major factor.
Are the coins going to be place in a coin book, and are you interested in the history behind the coin? Are you purchasing that coin to keep in a collection, and don't have any real plans of selling that coin?  You can see where I'm headed with these questions.
Investors are not interested in the enjoyment of the coins, and for the most part not collecting.  They are buying a commodity and hoping that the market goes up, so they can make a profit.  Or perhaps a person is buying gold and silver as a way to protect their family financially in the event of a major financial crisis.  Either way, the metal content of the gold and silver they are purchasing is far more important that the rarity.
One last thing to note, is that a person can both invest and collect.  Perhaps you have a nice collection of morgan silver dollars, but you also purchase junk silver(old quarters, dimes and half dollars) just in case the dollar crashes...