I practice Smith & Wesson myself.
I practice Smith & Wesson myself.
That's a good supplement to any MA.

I also like to add a little SIG Sauer myself!

I have mainly been involved with Shotokan Karate and Ryu Kyu Kobudo (traditional Okinawan weapons).
From time to time, our instructor would bring in guest instructors to give us a little exposure to other arts. I have carpal tunnel syndrome, so I found Judo would be a very bad idea for me since it requires a lot of wrist flexibility. Karate, on the other hand, is all compression on the wrist, and I can handle that.
It's not so much "flavor of the day", it's finding something that can work for you. Each art has something you can take with you if you have an open mind.
My father started me in Judo when I was a little kid, and I've studied various schools of martial arts throughout my life. Any form of martial arts training is useful, but many schools are geared more towards competition than practical application.
The primary point of any of them is learning the techniques and muscle memory training so that the various techniques become reflexive. If you have to think about it, it's already too late.
Self discipline is also an important aspect with any school. It's always better to walk away when possible and fighting is a last resort measure.
I think the best form of defense is to be somewhere else. Martial Art training is great, but you only have to get unlucky once in a fight.
I've studied Lau Gar Kung Fu and Kick Boxing for some time. I've given up the competitive stuff now as my instructor very kindly pointed out "You're too old".
I would say find a class that runs on days that is convenient for you. Go and have a look and talk to people to see if you like it. A decent class/instructor will probably let you pay as you go for a few lessons and will let you just watch to see what it is all about.
If they demand a huge sign up fee and that you buy all the gear immediately be wary. There's too many McDojo's out there that just want your money.
If you join a club that is a chore to get to you're more likely to give up when other things get in the way (work, family, winter weather). Likewise if you don't have fun when you're there.
Check out MartialArtsPlanet.com for information about all sorts of styles and instructors.