It's not a designer bag, but my Jack Georges' tote (big enough to store a 15' laptop) has been my trusty workhorse since 2009. I take it everywhere with me for overseas work-related travel. It has been thrown onto the back of trucks, airport security, endured torrential rain numerous times and despite all the maltreatment, it is still alive and well. The leather is pretty scratch resistant and the shoulder straps are wide and comfortable (I can't stand women's bags which are supposed to hold laptops but come with skinny straps - they are so uncomfortable and offer minimal support).
I'll probably need to replace it soon, but it has been my constant travel companion, it'll be sad to let it go.