Graduate studies in mathematics in usa?

hello from bangladesh,i'm currently enrolled into mathematics 2nd semesmter.i'v about 3 years left to done this undergrduate program at a local university. my grades are good enough.i wish to pursue graduate studies in usa in a good college.could u please name some good universities to do graduate and post-graduate in mathematics.i know i gotta take GRE and do real good. do i still have to do extra curricular activities. i play for the university basketball team anyway. and we have already achieved 3rd place among all universities in bangladesh.atleast that means i am good at basketball. is that helpful