Hey, these are my top two schools as well! I got accepted to both and am trying to decide between the two. I actually live in Charlottesville, and I've always had a connection with UVa and thought I would end up there. But Notre Dame attracted me because of the combination of strong academics, Catholic heritage, and ample social opportunities. I visited both schools within 3 days of each other--attended classes and stayed in dorms-- and was able to make a good comparison. First, I really liked both of them. In general there are pro's and con's to each. I may be biased, but Charlottesville is a great town, voted #1 place in the US to live a few years ago. There is always a lot to do such as concerts (U2 was awesome), the corner, downtown mall, etc. Theres also a lot in Va-- mountains, the beach, near D.C. South Bend has a more blue collar feel, and it sounded as if ND is less integrated with the town. The midwest is also not that interesting and the weather is pretty terrible, which I noticed when I visited. However, I really liked the Catholic feel of ND. It is definitely present everywhere, but certainly not overbearing. The ND students all seemed to love the school and had an incredible amount of pride. Not that you won't find this at other schools, but I think it speaks highly of the atmosphere and mission of the school. The campus is one of the nicest I have been on and is stunning. In contrast, UVa certainly doesn't have the Catholic presence and it does feel more like a public school (although an extremely nice one at that). That's not necessarily bad, its really just what you're looking for in a school.
Academically, I think ND is slightly more selective in admissions, but both are very strong in that regard. ND does have a strong alumni network throughout the country, and I've heard from numerous graduates that this can be very helpful later on. However, I personally know people who have graduated from UVa and gone to grad school at MIT, Stanford, and Princeton to name a few. I'm planning on majoring in engineering, and I think UVa's department might be ranked slightly higher. I know more about the engineering department, but in general here's the main differences:
Notre Dame has first year studies, which all students take whereas at UVa you apply to your school of study. Also, the Notre Dame students were telling me about elective requirements for all majors which include theology, history, and PE (not a generic gym class, but cool stuff like dodgeball, scuba, basketball, etc.) Some of these are fulfilled in addition to the first year classes during your next three years. I got the feeling that ND was trying to use this to provide a more well rounded education. Most students I talked to liked this, as they were able to pick specific classes within the broad categories. At UVa, the engineering students seemed more confined in the engineering school, and interacted less with the other departments. All in all, however, both are great schools and I think the academics are both on par with each other. For me personally, there are so many other factors to consider and I don't think you can't go wrong either way.