I actually deal in bullion on a daily basis and people ask this question all the time. You pretty much have 3 choices, each has its pros and cons.
1. Sell to a shop. Coin shops or pawn shops will buy your coins all day long. But as bherring1964 mentioned you will get a percentage under spot for their service (5%-10%). Pro- quick sell cash in hand Con- you lose a chunk of cash for the convenience.
2. Sell yourself. Craigslist is an easy way to find buyers, and you can usually get a premium on the bullion $50 to $100 over spot depending on the market. Pro- extra cash! Con- time consuming and people are a pain to deal with in these situations.
3. Sell to a bullion company. Kitco and
APMEX come to mind first. They buy and sell. Depending on what you have you may lose a few dollars or gain a few dollars around spot. Pros- close to spot price and easy. Cons - Don't expect speedy service unless you want to pay for it. Kitco charges a $40 surcharge for a bank transfer and $20 to fed ex you a check. Don't forget you have to ship your coins to them, and insure them.
So like I said they all have the positives and negatives, it all depends on how much time you have to search out a great price, and how quick you want your money. They are all reputable ways of selling your gold though.