What Type of Backpack Should I Use for Traveling?

The green backpack is my High Sierra backpacking backpack that I bought online. You can find a good price on Ebay or Amazon for these.  I love mine, it's great.  The orange backpack is my smaller backpack that I bought at Target and I wear it on the front of me.  It is my carry-on item in which i keep whatever souvenirs that I buy in it.  The smaller backpack in the front is what I use to carry all of my valuables and important stuff like my money pouch, passport, etc.  I bring this everywhere with me, even to to the bathroom!  This one I bought in Thailand but I usually had a light Adidas sports pack that I used.  I gave that one to a kid in the Philippines who didn't have a backpack for school.