LD34 happen to come on a weekend I had no plans and I ended up making a game with my 5 year old over a few hours for the most part (http://www.kongregate.com/games/8bitthirsty/a-knight-in-a-cave-ludum-dare-34-jam). I had a lot of fun but didn't really participate too seriously with my submission and it was really cool checking out what everyone else made. Cleared my schedule a bit more for this one so I am hopeful my game will turn out well.
I have done quite a few other game jams and I do highly recommend them. They have all been fun for me and I don't get burned out working on a game when you have such a short timeline and you know people playing aren't expecting perfection. The only thing I was a little bummed about with LD34 is that I didn't get many plays on my game or much feedback but I didn't put much effort into promoting my game outside a quick tweet/facebook post/C2 forum post and there are tons of entries so that is an area I really hope to do better with.
I would suggest everyone remotely interested go into it with an open mind and come up with an idea and run with it. Don't worry about polish and don't stress too much over the parts of game development you aren't as into. If a game doesn't have good or any sound or polished animations its not a big of a deal.