I have always found the law building to be a good study spot. There are also some nice open classrooms in science hall and the 4th floor of college that are usually pretty quiet and make for good study spaces around finals time.
I like studying at the Law Library over on Bascom. I enjoy it because of the crazy architecture, quietness, and the big windows overlooking the hill. Only downside is that only law students can study there during finals.
I like to study in the basement of 1410 Engineering. There are a ton of tables and outlets and most people do not know about it. I always have tons of room and have never been close to not finding a spot. It is in a basement, but that does not bother me as most of the time that I am studying it is below freezing outside anyways 🙂
I spend most of my studying in Engineering Hall and ECB. I like ECB for the lack of crowds, even on weekdays, but prefer Engineering Hall for the better lighting. Generally, I avoid Engineering Hall during class time as it has a tendency to be crowded and noisy.
As a third option, the WID can be an excellent place to study. Although it could use more tables and outlets, the lighting is great, and the building has the perfect level of ambient noise.
I like the hidden big room in memorial library on the second floor through the south stacks. Being surrounded by many people in a quiet environment makes me feel like I need to be focused like everyone around me.