What is a good toy for my cat?

okay, so basicly, the only thing remy (my cat) plays with, is a string. he LOVES strings. no fluffy, chewy, animal-type things. just, string. so I was wondering, is there like a fun play toy stringy thing at a local pet store or target/walmart? or is there a type of relistic, remote-controled mouse? because he LOVES hunting, and I have tried a remote controled mouse yet. so any ideas? (p.s this is for his presants for crismas)