Zynga is the company that is responsible for most (all?) of the games on Facebook as well as other social networking sites. What games do you play and why? Here's my list (played on FB):

Farmville: Level 29. The first game app I played, this one is also the most click and time intensive. I don't know why I like this game, but it does have some pretty cool things you can get. Only takes a relatively small number of friends to help out and max farm size. Lag is pretty bad if you have lots on animals on the farm. The music is really annoying after a while, and I've played the game muted since level 5.

Cafeworld: Level 4. Got this one mostly to help out friends. The bad AI pathing makes this game frustrating for me.

Fishworld: Level 1. I have an empty tank, after all my fish died ;D. No interest in playing this, but I got so many gift requests and invites that I d/l it to help out friends.

Yoville: Same thing as fishworld, but I think I'm level 4 now somehow.

Mafia Wars: One of the coolest apps, I'm level 49 now. If you don't have tons of friends or subscribe to a mass email list, you will not be able to PvP past level 15 (well, you can, but you'll lose a lot). I lose a lot.

School of Magic:  Level 30. I'm undecided about this one. There are not enough quests, and, like Mafia Wars, you have to have friends and gear to PvP well. I'm thinking by level 40 I will be completely outclassed in PvP.

War Metal: Level 18. This game is fairly new but pretty decent, maybe the best. The things I like about this is that is doesn't slow down my PC, doesn't take long to play, is more strategy based than numbers based, and doesn't suck up my time. There's also no cheat guides for it. Worst thing is that inviting friends is utterly fubared, and the tons of different tokens you rarely get are hard to keep track of. Friends are important, but not nearly as much as SoM or MF.

Castle Age: Level 9. Like SoM, but more developed. The best feature for me is the two-tier PvP system, which allows duels based on clans or on only you and your opponents stats and disregards # of friends.

Ant

I know about most of these games, but haven't been interested in playing many of them, despite numerous invitations. But maybe I will try my hand at one when I've got nothing else to do.

Basically the only applications I use on FB are the "Send a Heart", "Collect Smileys" and things of that nature...which aren't really games per se (and probably aren't made by Zynga), but I feel those have a friendly vibe to them. There's also DogWorld, which my mom and I both joined last year to help save real dogs, but that application was discontinued in the middle of last month, which made both of us very sad. :\'( :\'(

I go on my daughters Facebook and do the Farmville game for her.

Two weeks later...

FV: Haven't played this much lately, just planting crops that take a long time to harvest.

CW: Decided to give this another go. Level 14 now, this game is completely unplayable on my PC due to horrific lag.

FW, YV: haven't played

MW: still playing this, PvP isn't as bad as I thought it would be - lots of people level quick with small mafias, so they are easy marks.

SoM: I've come to realize this game totally blows, and almost no one plays it. I'm probably going to delete this app soon.

WM: this is not a Zynga game. I've been playing it, it's fun.

Castle Age: probably my favorite game now. It has better dynamics than WM, and since you can't buy good gear with real money, the playing field is very level.

Ant