I just finished a huge sale about a month or so ago (about $1400 worth of console/arcade games, spanning probably over 100 items) and was amazingly pleased that I was able to do it 100% via forums and not have to resort to eBay. Unless you don't have a particular value in mind, eBay destroys your profits. Let say you value a game at $50 personally, but you know you need to "lure" people in with a "good" deal. So you list it for $40. And by chance it happens to be the week that not many people want it and you get 2 bids, the winner being $41.75. After eBay and PayPal take their cut, you are probably getting $35 on a game you wanted to get $50 for.
I used a handful of forums including this one, neo-geo, arcade-otaku, and assembler. Neo-geo was a dream come true. Those guys placed orders consisting of many games, not just onesy-twosey. Many orders were well over $100. I can't guarantee you the success that I had, but my experience was great.
That being said, take good pictures of each of your items so that people know exactly what they are buying. You'd be amazed at how many people will just throw money at something and assume that whatever they had dreamed up in their mind was what they were receiving. Then you have to deal with complaints, issue refunds if appropriate, etc., etc. It's best just to take good pictures, describe things to the best of your ability, and encourage people to ask any questions up-front. If you don't have an image host, I just use PhotoBucket. Just make an account, take your photo's, re-size them to something reasonable, upload them to the host, and put a link to the items in your forum sales threads.
Also if you go the forum route, make sure that you read their rules. The last thing you want is to kill sales because you fail to follow their simple protocol (for example, assembler requires that you have your user name in the item photo). Also, if you don't contribute to a particular community, your mileage may vary. I happened to luck out at neo-geo, because although I have a minute post-count, I've been a member for quite a while.
And lastly, get delivery confirmation. It's only like $.80 on USPS stuff and it will spare you from wondering if people are lying when they say they haven't received their package, and it gives you a leg to stand on if you need to provide them with proof that you did your part.
Let us know how it goes!

-ud