If you read Marvel comic books, then chances are you've seen ads for Dave's Comics. From the ads, you would think that Dave's is a large shop overflowing with comics. Unfortunately, while they may have a large selection available via mail order, most of their stock is kept in storage and is unavailable for browsing.
What they do have in the store are a variety of toys, posters, books, t-shirts, graphic novels, etc. etc. Lots of manga. The most popular current comics, and a few rows of the "standards" for browsing (Marvel and DC mostly). But if you're hunting for a particular back issue, save yourself the trip and contact them via their ad, since you won't be able to rummage through the stock anyway.