Hi there,
Very generally, the very TOP US MBA programs often are considered those with the strongest reputation (Harvard, Stanford, Wharton, MIT for sure). Then for US programs, Columbia, Kellogg, Booth, NYU I'd probably roughly put next for global reputation, and definitely within-the-US reputation, BUT generally the top 2 outside the US for global brand are INSEAD and LBS, and depending on what industry and what region and what company you are interested in or talk to, LBS and INSEAD and potentially other European programs will be regarded similarly to many top US programs, or arguably US programs outside of Harv/Stanf/Wharton/MIT or thereabouts. Also Said (Oxford) and Judge (Cambridge) are very highly regarded not only for their MBA/b-schools but also because a degree from Oxford or Cambridge is known world-wide.
So, lots to think about, and depends a lot on your goals!! I encourage you and applicants in your boat to talk with those working in and hiring for industries and companies you are interested in and ask for advice on how they regard different programs, if really concerned about it.
Yes rankings have exceptions and loopholes and you need to take with a grain of salt, BUT if you look at several years' of rankings or how schools perform over time, schools consistently ranked high, that gives you a good feel for overall reputation too. US News & World report for inside the US and solely US programs; Financial Times for global reputation and includes international schools.
Hope that helps!