It's a no brainer that Mann takes first place, and for many reasons. Manndibles, the private group and individual study rooms, and natural/bright lighting make this library less dull and that much easier to stay awake and motivated to keep cranking out homework. Also it's the only library besides Olin with a bustling social scene.
Pros: Athletes in CALS are known to study here (hello hockey players!), so plenty of eye candy to indulge in on your breaks from Blackboard.
Cons: It's known as Club Mann for a reason. Be forewarned that the second floor breeds group work and socializing. I'm convinced that some people go to Mann to be seen.
2. Olin
Despite being a huge concrete eyesore, Olin is one of the best libraries. Come here to get work done in the many floors and rooms or socialize at Libe with a coffee break. Watch out that you don't get trampled during finals week.
Pros: Libe Café, lots of study spaces available, helpful librarians, every book you could ever imagine.
Cons: Graduate students leaving their books in the stacks and/or kicking you out of their individual study desks. This always seems to happen when you have the most amount of work to get done.
3. Uris 
Home to the famous "Harry Potter library" this is the place to go when you actually want to get work done. Oddly enough, also a super convenient place to people watch. The computers on the main floor are great when you have 30 minutes to write an assignment and print it before your next class (oops).
Pros: It's open 24 hours and is the ideal place to pull an all-nighter on campus.
Cons: People sleep in the Cocktail Lounge, so watch out for drool on the desks.
4. Law 
Filled with graduate students of the Cornell Law School, this library looks straight out of a movie. Guaranteed to get you plenty of likes on Instagram if you snap a pic of the chandeliers and huge windows. Great place if you have a lot of reading to do, but not much else.
Pros: Conveniently located for those who live in Collegetown. Also super beautiful on the inside with great views. Very legit.
Cons: Good luck getting inside with the new keypad system. If you manage to maneuver your way in, good luck staying there: law students get pleasure from kicking undergrads out whenever they can.
5. Catherwood 
Conveniently located on the ILR quad on central campus, Catherwood is one of the best places to procrastinate on campus. Super stressed vibes on the top floors, but gets more chill as you move downward.
Pros: Super comfortable individual window seating that is perfect for naps in the middle of the day. Love the desks attached to Catherwood's super cozy chairs as well.
Cons: Usually very crowded and filled with ILR students, who can immediately tell you aren't in ILR when you walk in. Not a super welcoming environment.
6. Africana 
Less well known, but newly renovated, the Africana Library is Cornell's most underrated library of the bunch. A great place to meet up for group projects or studying for prelims, you can't go wrong if you bear the Ithaca tundra to trek out to the Africana Library.
Pros: Quiet and uncrowded. The place to go if you're in Greek life and your house loses wifi late on a Sunday night, or you're wearing a groutfit and don't want to bump into anyone you know.
Cons: It's in the middle of nowhere off campus, so it's kind of a hike to get there unless you are fortunate enough to have a car on campus.
7. Everything else: Kroch, Engineering, Fine Arts, Music
These are all kinda meh. Only recommended if you cannot secure a spot in the top six during finals week.
