For my undergrad degree, I chose based on the following criteria:
The school expressed an interest in me. Beyond the obvious impact of getting a full tuition academic scholarship, the school I chose paid half my airfare for me to fly out and interview for the scholarship and spend a couple days on campus. The van that picked me up at the airport also picked up four other students at the same time--and an admissions counselor was in the van who had obviously just read over all five of our applications and transcripts, as she began talking with each of us about specific organizations and programs on campus that would appeal to us individually. The large amount of personalized attention made me feel that I was individually valued, and would be unlikely to fall through the cracks at the school.
The academic credentials of the school. I knew I'd be going on to some form of graduate work--most likely a PhD but possibly law instead. I figured that it would be much easier to get into the grad program of my choice having a BS from a top-50 university than having one from outside that range.
The campus. I really wanted to have a true college campus, not buildings interspersed in a city. I know some people prefer that style, but I really appreciated that my campus was distinct from the neighboring parts of the city, and had trees and whatnot.
Finances. Ideally, they wouldn't really matter, but in reality...not having to pay the university tuition saved me over $85,000. Having that in a merit scholarship, as opposed to need-based grants, was also important to me personally. I almost certainly would have gone to another school if it hadn't been for an offer like that one.
On the newly edited version of this question, the things that would appeal to me at a convention of universities I hadn't heard of before:
- Specific policies for accepting AP/IB credit. I felt sandbagged when I found out that although my university had proudly stated that it granted credit for high scores on those exams (3 or better on AP, 5 or better on IB), they didn't actually waive most sequences courses, so I had to repeat a lot of coursework I had already completed and on which I had the highest score possible on the relevant test. I would want a university to tell me what the reality of their acceptance policies are regarding college work taken in high school.
- Acceptance rates of its previous graduates applying for further education, and which schools were the most frequent destinations of those who went on.
- Housing situation. What percentage of students live in university housing for 4 years? Of those who don't, what percentage left University housing truly voluntarily, and what percentage were unable to secure spots in the housing lottery?
- What sorts of study-abroad programs are available? Not only what cities/universities could you spend a semester at, but what sorts of courses would you be able to take there and count toward your program back at home? I would have liked to study abroad, but in the sciences it's often impossible because you have so many required sequential courses that are often not available in study abroad programs.
- A list of the student clubs and recreational sports available on campus. I'd like to be able to see that there were activities I'd enjoy and be able to meet people with similar interests.