I'm not a big fan of big box bookstores like Barnes and Noble. However, they tend to be the most common so, if I'm going to a bookstore, I usually to go to those the most. It's the small, locally owned bookstores that I have the most fun at. They seem to have the most ecclectic collection of books and it's always fun to see the local flavor regarding certain genres. Plus, who doesn't want to support the little guy?
I could spend days lost in the Powells bookstore in Portland, Oregon. It's huge, but it's no Barnes and Noble and the fact that they have a massive used book collection just makes things more interesting. One never knows what they will run into at Powells. Locally, however, my favorite bookstore would be Sam Wellers. They are Utah's version of Powells. They are small-fry compared to many, many other bookstores but for Utah it's pretty impressive. They have a large used book collection and do a lot of author events, signings and readings. This year they've had John Scalzi and Ken Scholes show up. I missed both of those readings and signings due to being on pregnancy induced bedrest, but I was still excited that those authors showed up. No other bookstore in Utah usually has any SF author but our local Brandon Sanderson show up. While I enjoy his events, I also like having the opportunity to hob-knob with other authors as well - and Sam Wellers is where I usually turn for that.
I shop for a lot of books online, as well. Barnes and Noble doesn't carry a lot of what I want and we lost Borders a while ago so online is what I turn to in times of desperate need. While Sam Wellers is fun to browse, they don't have a lot of what I tend to be looking for. For online shopping, I tend to go with Amazon or iBooks for the iPad. For ereader programs, I like iBooks most, and the reason is, honestly, quite stupid. iBooks counts down "pages left in this chapter" and for some reason that thrills me (it doesn't take much to make me happy...). I also use Kindle a lot, which you can probably guess by my love of Amazon. With a new baby I don't have tons of room for new books so I'm trying to either get all my books from the local library (which has an AMAZING collection, by the way - much better than any local bookstore I could go to) or get ebooks because they take up no room.
So those are my favorite bookstores. I know there are a lot more out there that I haven't used yet, so I would like to know what your favorite bookstores are and why. Maybe you can broaden my horizons.