It's confession time: if we could only buy one accessory forever, we'd buy bags. First of all, we've got phones and wallets and lip gloss, and we need somewhere to put them. Plus, they're just fun to look at. If you're in the market for a new carryall, our advice is to invest in something classic. You know, the picks that go with every outfit. Sophisticated and elegant, these 15 bags are always winners.