Out of the one's in the list, I voted for Princeton. In my view, it has the strongest undergraduate engineering department out of all the Ivies. I would've voted for Cornell if it provided a better overall college experience. Penn isn't that strong, but Harvard is. Plus, if you enroll at Harvard, you can cross-register classes at MIT (and vice-versa).
I'd rank other American schools like so:
1. MIT
2. Stanford / Berkeley
3. UIUC
4. Caltech
That's undergraduate, btw.