Am a CSI Las Vegas addict, and started purchasing the dvds at Best Buy. Some of them were worth purchasing directly at the store, others were not. Definitely check online pricing and availability before going to the store. However, overall, I would purchase at Best Buy before others due to availability of all the seasons, pricing, and for the rewards points which give back for future purchases. Great movie selections as well.
What's great about it: price, availability, order/purchase online, able to start watching immediately, add to rewards points
What's not so great: not all seasons of series available at similiar price