I see others have mentioned the Buffalo & Erie County Library (NY), the Philly Free Library (PA) and the New York Public Library.
1) Queens Library (NY):
2) Brooklyn Public Library (NY):
3) Fairfax County Library (VA):
* By the way - you can get a library card from Fairfax County Library by mailing in an application & $27 USD. It's good for one year. For the New York ones, although you can sign up online, you have to validate your card in person within a certain number of days.
4) And my very own local library - OWWL (Ontario, Wayne, Wyoming & Livingston county library system):
As they are "my" library - they are the first ones I check with and I always get books from them if they have them. They are building up their collection (very small library system) but are great. It's a money issue...
One of my favorite things is to open one of these library sites and select for a format (usually ePub) and have Overdrive show me only those fiction books that are available for checkout. Almost like wandering the shelves at the local library...
Browsing the library whilst at home! I like