Another data point - I trained in Aikido for several years, and enjoyed it tremendously. I eventually moved away from my dojo and couldn't make it often enough, so I stopped, but I highly recommend it.

It's been particularly helpful in defending me "on the street" - it taught me to be really good at falling without hurting myself, which is an incredibly practical self-defense skill. It's come in handy many times on icy Michigan roads. I'm not looking to start a fight, and I've never been ambushed by ninjas, so striking arts haven't really appealed to me.

Capoeria looks like a lot of fun, too.