Answer tomorrow. It was fun for me to discover who they were. Two will seem obvious but the third one might not. I imagine alot of people will go to Baseball Reference or use the Lee Sinins Complete Baseball Encyclopedia. Two are among the all-time greats (one is a household name while the other is among baseball fans, too) while the 3rd was just very good and is probably not a household name and maybe never was.
I did this search because a question came up in the Hornsby chapter of SABR. Who are the only two guys with 1200+ RBIs, 250+ HRs, 300+ SBs and 3000+ Hits?
Answer: Willie Mays, Joe Morgan and Vada Pinson