I don't think there is any other famous teacher now, but the same can be told about the absence of true leaders these days. I think people are just getting too individualistic, and everyone has their own guru, fashion, Facebook and Second Life. We are dealing with so called "You Tube generation" and not pro-peace student movements of the 60s.
Personally, I think that Osho is the name of the past. He came in with sex tantra in the 60s, when the West was starting to explore spirituality (and sex). Now this is all available. People want something more real. Your sister will probably have fun with Osho people, but I hope she won't stay there forever.