Games

I had one main requirement for a flash gaming app: Desktop Tower Defense. Of the various game apps -- and there are many -- Games from RockYou! meets that requirement, and also integrates with Facebook better than most flash game apps. Flash games + Facebook = very little work getting done.

Matches

Matches is about secret admirers. If you have a crush on someone, list them as a match, and they won't find out unless they also express interest in you. Of course, there is a slight flaw in this app. The app tells users when someone has expressed interest in them, and because Facebook lists which of your friends use each app, unless most of yours have Matches installed it should be pretty easy to figure out who has that crush.

Bookshelf

There are enough Facebook apps for rating and reviewing your book collection that they could fill out their own top 10 list. Bookshelf is neither the oldest nor the largest, but in my opinion its the best, even though it is a bit rough around the edges (I got some error messages, and some people have had some trouble importing from outside services, like LibraryThing). Bookshelf supports books, DVDs, games, and music, and lets you browse not only your friends collections, but also those within your network. Bookshelf also makes pretty accurate suggestions based on your Facebook profile before you've even added an item. The developers were smart to include an invite form as part of the install process, which should help spread the app faster.

BandTracker

BandTracker, an app from classifieds site Oodle, lets users track over 200,000 different bands and find out when they're coming to play in their area. The app also lets you see who your friends are tracking so you can find new music, or hook up with buddies to go to shows with.

Food Fight!

Food Fight! is one of the more silly apps on Facebook, but so far has already attracted nearly 1.8 million users. The premise is simple, each day you earn money with which you can purchase food to toss at your friends. The creators of the app have cleverly sprinkled ads for their other Facebook properties all around the Food Fight! applications, which has led to them owning a handful of the more popular apps on the platform.

Quizzes

Quizzes is an app that lets you create a quiz about yourself to find out how well your friends really know you. Which of your friends knows your nickname or your favorite pizza topping? Back when I was in high school, there was an app like this for AOL Instant Messenger profiles that spread like wildfire, and Quizzes seems to be doing just that with over 1.7 million users in just a couple of months.

Pets

There are multiple virtual pet apps on Facebook, but the simply named Pets is the only one I could find that adds elements of a role playing game. Pets lets you build up your pet's strength, buy gear for it, and then battle with other pets. Your friends can even help you out by petting or feeding your virtual pal. You can think of it as something like Pokemon for Facebook. Unfortunately a couple of features are disabled at the moment.

Honesty Box

Of all the requests I get to install applications, I get requests for Honesty Box the most -- I wonder what that means people want to say to me. Honesty Box is an app that lets your friends leave anonymous messages for you, both positive and negative. If your friends are too polite to let you know your new haircut makes you look like Herman Munster, then perhaps installing Honesty Box would be a good idea. Unfortunately, because Facebook tells you which of your friends have each app installed, this app suffers from the same flaw as Matches.

Stories

Being a writer, I had to include a collaborative writing application. Stories lets you write stories with your friends tiny bits at a time. There are a few annoying things about this application (like if you don't fill out all the required fields it erases the ones you have filled out -- including whatever you're trying to add to the story), but in all it is pretty fun, and ideal for silly stream of consciousness collaborations created with friends.

Scrabulous

If you're like me, you love Scrabble but aren't too keen on the board set up and random letter tile distribution of Yahoo!'s Literati game. Enter Scrabulous, the companion Facebook app of a web site by the same name. Though likely infringing on any number of Hasbro trademarks, Scrabulous is a faithful reproduction of Scrabble game play that would make any logophile happy. It's not real-time, but that's actually not so necessary as Scrabble can be played one turn at a time.

Conclusion

Those are the top 10 Facebook applications that for play. Which apps did we skip that you think should be in the top 10? Which apps shouldn't be on our list? Please let us know in the comments. And be sure to check back in tomorrow for part 3 of our list. Let the debate begin!