Year 1 (2003) was at a nice local restaurant (that no longer exists) in a room just for us, with a silly $10 gift grab. I still have the plant today that I got in the gift grab!
Year 2 (2004) My boss had had a house built this year, so we had the party at his house. He hired a caterer and set up fancy tables. The twist this year was that we each had to bring some form of entertainment for the group, and it would be judged! The presentations were widely varied (I matched each co-worker with a breed of dog and explained why, one boss sang like Kermit the Frog, one co-worker made a work-related board game, one person wrote poetry). While fun, it was really stressful and I think made us all dislike this party the most. Competition doesn't fit well with a nice formal party!
Year 3 (2005) was the year of lavish gluttony. Our company was doing well, and the owners wanted to take us out to celebrate wealthy style! They had reserved the private wine cellar room at arguably one of the most expensive restaurants (for sure the most expensive steak restaurant) in town. Not only could we get whatever we wanted off of the menu (steaks started at $60 for JUST THE STEAK!), but we had appetizers galore, wine, and dessert. I still feel guilty to this day about how much that meal must have cost, but it was a one-in-a-lifetime experience.

Year 4 (2006) was my favorite party to date. It was our first year in the office space we owned (a cool old house), and my boss's hired the chef/somalier at a local winery to come cook us a 6 course meal with a wine pairing (from their vineyard of course) for each course. The wine was presented with an explanation about it and how it paired with the food being served. They rented tables and set up the office beautifully, and the food was amazing. The entire meal start to finish was 5 hours! We then each got to take home a bottle of wine from the vineyard.
Year 5 (2007) was a multi-pronged party. We started out a Sur La Table and had a cooking class (and we got to eat the food). I remember it being haricots verts and a meaty soup, but I know there was other stuff and it was very good and a unique twist on the usual dinner. We then walked a couple of blocks for a performance of A Christmas Carol. After the play, we had a private room at a local bar/restaurant for dessert and drinks. Although this was a fun year, I missed the ability to socialize more. I did learn about the greatness of meyer lemons though :)
Year 6 (2008) was at the View Point Inn, about a 45 minute drive for most of us. Part of Twilight was filmed here the same year as the party. It is a beautiful building with a gorgeous view. Unfortunately the party was in the evening, so we didn't get to enjoy it. We did enjoy the cocktail hour before dinner with the room just for us. Post-dinner we did a gift steal. The boss had given us each $20 for a gift. The best part of this steal was the rapid-fire dice tossing for the last minute. You got to steal the gift of your choice if you got doubles. We ended up with a gift certificate to a local restaurant, which was great.

Year 7 (2009) Unless I work for them doing some consulting in 2010 (fairly unlikely), this will be my last party. It's a tight year all around, so the plan is to start at the office with drinks and games, and have dinner at a local upscale grocery store that does dinners. We'll be doing the same gift steal as last year, although the twist is that the winner of the games gets final pick of the gift they want.
I'm going to miss these parties! I have so many great memories of the fun we've had and how appreciated we feel/felt as employees.