I took judo in college and have nothing but good things to say about it. My judo instructor also taught an introductory hapkido course and that was pretty cool, too.
What kind of jiu jitsu is it? I’m planning to start taking Brazilian jiu jitsu here. The instructor also teaches tae kwon do (sp?) and from his description, if self-defense is your goal, then go for the jiu jitsu if it is the Brazilian type. He said in no uncertain terms that someone who had taken three months of that would beat one of his tae kwon do black belts with little difficulty. I took a little Japanese jiu jitsu one summer, I don’t remember which style, and I wouldn’t recommend that. But that instructor was too formal and wrecklessly dangerous… The school of jiu jitsu will greatly affect what you actually learn. The Japanese style I did that summer focused almost exclusively on standing techniques, whereas the Brazilian seems to be concentrated on ground fighting.
If you’re looking for exercise and something you can persue in the long term, I’d recommend judo. No punching & kicking means that it is easier on your joints and it is designed specifically to be safe to practice. That also means that you can train harder which will prepare to apply a throw for real if you really have to.
I’m skeptical of anybody who says that judo isn’t good for self-defense. A simple throw will hammer your opponent into the concrete with significant force. Some throws are truly crippling to a naive attacker on pavement. O soto gari, one of the first five throws you’ll learn, will take an opponent from standing to flat on his back in about a half a second. Well practiced and slightly modified, you will be able to take a standing man of appreciably greater size than you and literally plant his head in the pavement before any other part of his body touches the ground. Since not many martial arts focus on standing throws, relatively few people will know how to block a throw.
If you want to learn hand techniques, i.e. standing joint locks, then I’d recommend hapkido. From what my instructor taught in his intro course, it is a pretty rounded style. I don’t know if it involves ground fighting. It did involve punching & kicking as well as joing locks and that sort of thing. Worth noting, he said that hapkido is different from every other martial art in a very important way: they start teaching few techniques and you learn more as you advance, whereas in hapkido you start learning lots of techniques and then start pruning down until you have a handful of techniques that you can apply reflexively. He said that when he got his first black belt (which wasn’t in hapkido) he found himself in a fight and got beat up because he didn’t know which thing to do. There were so many tools in his tool box that he couldn’t choose quickly enough. With hapkido, according to him, the opposite is true. You’ll have a small tool box of effective moves that you can use instictively.
So there you go. The tae kwon do instructor says to take Brazilian jiu jitsu if you want to learn self-defense. The judo & hapkido instructor says hapkido will leave you with a small toolbox of effective moves you can apply instinctively. And the guy who took judo in college says that judo may be a sport, but when you use the concrete to crush somebody’s skull, dislocate a shoulder, or break several ribs, what difference does it make?
As a final note, philosophically I really enjoyed judo the best. Although you may find your instructor to be of the spiritual view, judo is essentially a pholosophically materialistic sport. For example, when I first started one of the black belts told me that I should yell when I throw. Asked why, he said, “It is supposed to do with some spiritual crap, but actually it just gets you more points.” (Because if the throw ends up being too ugly, the judges knows who acted with intent.) Judo is basically applied physics. And like all physics, it is accessable to anyone. There is no intangible forces to contact, no psychic powers to harness, no superstitions to adhere to. I like that. And since judo is a truly full-contact affair, much like wrestling, what succeeds on the mat is what is effective to throw you opponent with force, to choke him unconscious, to make him submit with an arm lock, or to pin him for 30 seconds. Moves that prove dangerous are cut from the sport. Moves that don’t work are not taught or used (except for belt tests).