There's many in the US that do, I can't really speak to elsewhere. It's hard to make a comprehensive list. Just check different database site and see the turnaround times.

Hey guys,

I have just begun getting into autograph collecting and was wondering which actors or celebrities in general have good chances of signing? which have yous had good experiences? As I don't want to be sending letters with false hope whilst wasting money on stamps etc.

Thanks for reading and all feedback is appreciated!
Mark V