Personally, although I love satchels, for grab n go, on the run type bags, I find crossbody or shoulder to be the best, which is why I voted for the hippie.
Another suggestion, if you shop on ebay, is the mia convertible shoulder, regular size. I have this bag and use it as a casual grab n go bag. It can go shoulder or crossbody, and holds a good amount without being huge. the leather is super soft and smooshy too. its a very simple, clean style.