Oh, man, I loved that Expos cap! Seriously!
I also loved this one from the Padres (well, actually the one before this, before they added the orange outline stripe and orange airholes)...
...and this one is my all-time favorite...
Others I really liked:
If you'll notice, every one of those caps has two things in common: 1) they're from the mid-70s when I first started following baseball, collecting cards, and studying and admiring the uniforms, caps, and helmets of the teams and 2) they're colorful. I'm very much a traditionalist when it comes to baseball uniforms. I don't like alternate jerseys and the proliferation of black, for example. But I really loved the bright colors of the 70s.
Yes, some teams went way overboard (Padres, Pirates, Astros, Indians Bloody Mary, etc.), but the earlier versions of these teams uniforms (early 70s, before they went wild) looked very nice. There's WAY too much black and navy in the game today. It's good to see some teams starting to go the other way and introduce bright colors once again.
Have you noticed the Orioles uniforms lately? They've switched from black lettering to orange, and wear the orange-billed caps much more often than they used to. (Now, if they'd just go ahead and paint the orange bill on their helmets and make that the primary...) And the Red Sox have brought red back to their uniforms in a big way, replacing all the navy. As I mentioned before, the Royals are dumping their black next year in favor of golden yellow trim to go with their royal blue.
Color is good, as long as it's done properly, and that means within the confines of an all-white or all-gray uniform.