Actually Samsung has used some proprietary ports in the past and still do on things like the Galaxy Tab 10.1. Also I believe HTC used one on the Eris http://androidforums.com/eris-accessories/287777-different-eris-charging-port-not-mini-usb.html. The iPhone is probably just the most well known. The good thing about the iPhone port is even though it's proprietary if you're around 10 people at least half are likely to have the same port on their phone and may have a charger you can borrow.
I have issues with some car chargers, but not wall chargers. I *only* have problems if I use a charger that my hubby uses regularly for his Blackberry. He can use mine occasionally and I won't have a problem. But if I try to use the ones he uses regularly, it has a hard time keeping the connection to keep charging.