Nothing says long term relation like gold and silver. In this age of economic uncertainty, silver coins make a wonderful Valentines Day gift.
The whole point of coins is that they contain a known amount of precious metal. Old US coins are popular because they contain a known amount of metal.
The new Liberty Dollars contain exactly one ounce of silver. So, they are even easier to value. Every household should have a few hundred dollars in silver on hand in case there is a disruption in the monetary system.
Silver tends to hold its value. In 1913 an ounce of silver would buy a romantic dinner for two.
Silver is currently (1/31/2012) trading at around $33. Three ounces of silver bullion coins costs around $100. (Coin dealers tack on shipping costs and a premium). I tend to buy coins on eBay. Here is my list of online coin shops.
If you buy silver at a local coin dealer, tell them you have absolutely no interest in numismatic values and just want silver coins ... they will give you a better price.