In terms of prestige, the closest proxy is the US News rankings which take into account responses to reputational surveys. Also, as mentioned in other posts, the US liberal arts colleges are uniquely designed to foster a broad based education coupled with more intense writing and tutorial based learning, i.e. debate and discussion in smaller seminars and one on one sessions with professors. That said, from a US perspective there is a high regard for the Canadian schools and education system generally. If you plan to live and work in the US, it would make sense to attend a Williams or Princeton instead of McGill. Williams and Princeton also have a good track record placing their grads in the top grad and professional schools in the US. Applying to these schools from McGill may be more difficult. Also, if you plan to return to Canada, going to Harvard for undergrad and then grad school in Canada would also work well. The network you access at these US “prestige” schools is also an important factor. So, in all scenarios, attending college in the US at a well known LAC or Ivy would be preferred to McGill; however, McGill is definitely similar in prestige.