<p>Allow me to take a boring, middle-of-the-road approach:</p>
<p>In the case of Cornell engineering vs. other Ivy League engineering, it's perfectly sensible to choose Cornell, because "engineering" is a "school" in and of itself. Sure, people often change majors and whatnot, but an eighteen-year-old who says, "I want to be an engineer," is not unreasonable (assuming he/she has put thought into it). It's when he starts saying, "I want to be a mechanical engineer," and starts looking at the best mechanical engineering departments and ignoring all other forms of engineering and sciences, that he's taking things too far.</p>
<p>Areas like "engineering," or "architecture," or "art," or "science" are obviously not specific fields, and if you feel like you belong in one of these general areas, then by all means investigate colleges that specialize in these (not everyone has the luxury of attending a school that is supremely awesome in everything). Just be careful about getting too specific. For example, if you're interested in social science and economics in particular, the University of Chicago is an obvious good choice, as it is top-notch in economics and is also strong in areas you're likely to convert to (math, political science, history, sociology, etc.). Contrast this with MIT, which is also top-notch in economics, but if you decide to change your major, your little social-science-loving-self is rather screwed.</p>
<p>Oh, and in closing I'll make the obligatory remark that "fit" is more important than anything else.</p>