I've been doing Wing Tsun kung fu for over ten years. If you find a good school, it's a very methodical, highly intelligent and very technical martial art. There's a lot of depth to it, and as you get better, it gets more and more subtle (as well as a lot more effective). Unfortunately, there's also a lot of schools that are not very good (as with any martial art), so your experience may vary. In my experience, the german (Leung Ting) branch of the art is the best at this point. We have a few ex-fencers in our class, and they seem to enjoy it a lot.

The style itself is a soft style, relying on speed and sensitivity to deflect the opponent's attacks and triumph. A lot of the training is partner-training, a lot of it is playing role games. As you get better, we also work on the psychology and tactics of the fight. I've been doing it for a long time, and I have never gotten bored with it - there's always people who are measurably better than you to serve as a reminder of what you're striving for. In many martial arts, once you hit a certain plateau, there's not much difference between someone who trained for five years versus someone who trained for 10 - here, the difference is clear as day.

The other thing I really enjoy about our school is a very well structured curriculum - you always have very specific goals and targets to work on, you get tested every 3 months, and the teacher always keeps track of where you are at and that you're making progress.

If you're in the SF Bay Area, send me an email (my username @ gmail), I can give you an introduction or an invite to class.

Most martial arts schools offer free or discounted introductory lessons. You can attend a class for a month or so to decide whether it's something that suits you.

How WT compares to other martial arts (that I have any familiarity with):

Aikido - softer, more traditional teaching style, so it can take a lot longer to get good at it. Similar concepts in terms of deflection and redirection of opponent's attacks; not as aggressive as WT.

BJJ - focuses on tournament-style fighting with certain rules - great for locks and ground fighting, but there's a reason that most people who take BJJ also take Muay Thai or another striking art at the same time - BJJ doesn't cover those areas well, if at all.

Muay Thai - amazing cardio, amazing for working on your balance, but more brutal and simple, not much technique or sensitivity involved.

Krav Maga - another very physically strenuous workout, but focuses on a set of very simple techniques. Not much depth to it, after six months or so you probably know most of what they have, after that it's just about getting stronger/faster.