My favorite bookstores are Powell's in Portland and Moe's in Berkeley.
I worked in Portland from 1987 to 1993 and was in Corvallis from 1994 to 1998.
I was in Berkeley in all or parts of 1973 to 1975, 1977 to 1979, part of 1982, and 1985 to 1987, mostly as a student at Cal but also as a Fed employee.
In recent years long time brick and mortar book sellers in Berkeley have gone out of business such as Black Oak Books, Shakespeare and Company, and Shambhala Books (the publishing company remains but this was a most excellent esoteric bookstore).
Pegasus Books still exists on Solano Avenue in Berkeley (and now has other locations). I lived very near Berkeley's Gourmet Ghetto (location of Black Oaks) in 1985 to 1987 but liked to hang out and shop in the more sedate (than Shattuck or Telegraph) Solano Avenue business strip. I bought one of 100 limited first edition copies of the Underwood Miller Collected Stories of PKD off the shelves in 1987 at Pegasus and got turned on to Jim Thompson Black Lizard re-issues when they first came to market from Pegasus.
Other good books stores are The Strand in Manhattan, Elliot Bay in Seattle (but my understanding is that Elliot Bay has changed from what was a familiar location to me back in the 1990s), and City Lights in San Francisco's North Beach. These stores like the now closed Black Oaks and Powell's have (or had as recent years I have hid in mountains) regular author events.
There was Redding Bookstore (closed) in Redding CA that was quite nice with new books mixed with used (and good buyers) and an associated coffee shop forced out of business by the internet and Barnes and Noble. I found a 1st hc OTO edition of Crowley's Book of Thoth there (book #13) about 25 years ago.
A hidden book lover's gem in Redding is Cal's Books. Cal's Books is located in an industrial area with zero street traffic and is never very busy, hard to realize how Cal's has survived so long. The inventory is huge and rare and specialty books (and comics) abound. They also sell herbals.
https://m.facebook.com/pages/cals-books/115659681788145Eureka Books in Old Town Eureka is a quality bookstore and has good local collectibles but most of the quality used book sellers in the Humboldt Bay have closed shop in the past 20 years. Booklegger that sells used books a block from Eureka Books is OK and Northtown Books (new books) and Tin Pan Mailman (used books) in Arcata are also OK. I want to give a shout out to the gone for 10 plus years small Bohemia Books in Arcata that specialized in new and used "literature, metaphysics, and eclectica" and looked like the non-scientific part of my own library.
Blackberry Books and The Book Bin were OK during my time in Corvallis, some collectibles at Blackberry: 1st Edition with dust cover Electric Koolaid Acid Test and 1st Edition with dust cover Stewart's The Earth Abides. Blackberry's Books seems to no longer exist.
Ashland OR has a number of bookstores on a tourist oriented but funky commercial strip with good restaurants adjacent to the Oregon Shakespearian Festival complex. I was going to point out a favorite new / used book store heavy to the esoteric but cannot find a listing so also must be gone.
I went to a book festival at Hay-on-Wye in Wales back in the early 1980s.
I used to travel a lot for work when in Portland and always searched out local bookstores and made regular stops at favorites such as Elliot Bay and The Strand.