Alright...I'm going to break your rule of nominating only 1 person

I collect mostly sports...mostly baseball. There are a couple of guys out there that will sign your item and have it back to you sometimes in less than a week. These aren't just nobody players, but former MVP's, HOF's etc. My 2 fav's other than the previously mentioned Bobby Doerr are:
Marty Marion (1944 MVP)
8 Forcee Ln
Saint Louis, MO 63124-1245
USA
and
Phil Cavarretta (1945 MVP)
4637 Kellogg Dr SW
Lilburn, GA 30047-4407
USA
2 of the best signers around.