FYI for most batteries a quick charge degrades battery life faster so if you plan on keeping the device for a while, usb charging is probably the better method.
It depends, when I have an internet connection and as such use my MBP a lot I charge through that. When I am at my place in Laos with no net connection I use the wall charger. Although if I ever have a reason to be on my computer my iPhone is always plugged to it charging while I am working.
Have a radio alarm clock thing next to my bed, that has a dock my iPhone sits in and the alarm on the clock makes it play music that's on my iPhone which is pretty cool. So wall charger.