Immortal, I have a list as long as my dick of arts I would recommend taking over TKD, but if you decide to go through with it, at least do yourself the favor of finding a qualified teacher. There are waaaay too many McDojos out there these days teaching watered-down Billy Jack bullshit and giving belt tests for $50 every other week. Don't get scammed.
Eric, I would definitely recommend reading The Tao of Jeet Kun Do if you're interested in the idea, but don't buy too much into the "ultimate martial art" misconception like most people. If you think about it, "Jeet Kun Do" should be a principle that we all apply to every discipline in which we're involved.
Also, good luck learning ninjutsu anywhere outside of (or really, inside) Japan. There's a loooooot of phoneys out there and nobody teaches anything anymore that even resembles the techniques of classical ninjutsu. You closest you might be able to get is Taijutsu, and even that is probably inferior to other more developed forms of unarmed combat.