Sooo many possibilities out there. Yes, sites like Smugmug and Pictage can work, though I've never been a big fan of those. Zenfolio isn't bad, but they recently stopped offering a no-commission option on their shopping cart, so (if memory serves) regardless of whether or not you're doing self-fulfillment, they'll still take a cut of the sale.
I prefer solutions that let me take care of everything, soup to nuts. I currently use RedCart, though it is a flash-based system and I would prefer it not be. PixieSet and Shootproof are also popular systems that lots of people like. PixieSet is intriguing to me and I'm considering trying it out.
What you choose depends largely on how professional you want to look. I want a boutique experience for my clients from start to finish.