If you're buying silver at a bullion investment, then it should be tied to the current spot price and what form it is in won't matter a whole lot. You will find that the bullion coins minted and/or sanctioned by respectable governments, such as the Silver American Eagle series from the United States Mint, will be more easily traded and might have a slight premium over junk silver.
Thanks so much Peter for the great answer. I would probably prefer to go with the minted coins instead of junk silver. I like the looks of them very much so.
It is always a better idea to invest in silver coins rather than junk stuff. So, I would go with the expensive ones as you can be sure of them being authentic and original.
Hmm... It is always better to buy Silver bullion bars rather than silver coins. And I'd recommend buying upwards 10 oz. From my experience, I can assure you that unlike the case of gold, selling silver coins is always problematic...
