A 16:9 1080p 15" matte LCD display is the most ergonomic and economic choice I think.
16:9 is now the most common form factor, 16:10 would also be a good choice, but I dob't know if it's as widely available. It's a good format for both modern media consumption and productivity. 4:3 isn't really an option anymore, not if you want a modern laptop.
1920x1080 is the optimal resolution I think. Plenty of sharpness, yet not battery draining high. 720p for laptops is really getting outdated for modern machines.
15" is a good blend of productivity and portability. As a student, 13" is a bit too small to keep 2 documents open next to each other, 17" is a bit too large and cumbersome for students.
As for display finishes, I prefer matte. For outdoor use and my sanity. Glossy displays have beautiful colors, but the fingersprints drive me crazy, dust and filth aren't easy to clean and the glare can be really annoying. Matte is more a jack-of-all-trades coating.