I have rather plain jerseys (one red, one blue), I have a jersey from my LBS, one from a ride I did (a metric century), someone at my company gave me one (it's kinda cool, there's not many of them, and everyone I know who rides wants one), and I picked up a really cool one in London that has a map of the London Underground system.
Of course I also have the requisite AZ Flag jersey, that everyone who lives here has to have.

I'd pick up 2-3 now, and you'll be surprised how quickly your collection grows.

(and NO, bibs aren't a must, wear whatever shorts or bibs work best for you)