Among people I know, Srinivasa Ramanujan is one of the most famous mathematicians. Everyone thinks his problems are very interesting and important, and he is even somehow more famous than G. H. Hardy. But to be honest I don't think his problems are that interesting, and most of his theorems are just assembling long sums. It seems like a bunch of Indian tricks. I think Ramanujan is mostly famous because he is brown rather than for any exceptional insight in mathematics. An example of this is Ramanujan not being able to eat meat, which is a trivial application of the human mouth.