I go to B&N (usually the one on Westheimer near Sage, sometimes the one near home at Town & Country) if I have some time to kill.
If I know exactly what I want, I use Amazon.
I live minutes away from a shopping center called The Fountains, which has a Borders. There's a B & N down the freeway in First Colony. I sent an e-mail to Borders a while back complaining that their magazine rack contained NO CONSERVATIVE MAGAZINES. NO, NOT ONE. They did not have National Review, Limbaugh letter, American Spectator. Nuthin'. But they had EVERY LIBERAL rag under the sun. They actually responded to my e-mail, saying that they felt that conservatives already had subscriptions to the magazines they like, and that they did not sell well in their stores. It could be true, but I think it's BS. I was about to go on a plane trip, and wanted a conservative mag or 2 to while away the time.
I do usually know what I want, and far prefer Amazon. I hate going to stores and not knowing which section a book is in. Amazon's search engine, and user reviews are very cool. I'm a Prime® member, so i get everything sent 2nd day air from Amazon.