Cannot understand why anyone would not have Willie Mays near the top of that list. That 300 footer to take out Cox during the 51 pennant drive is just as memorable as "the throw" after "the catch" off Vic Wertz. Wertz hit the ball 450 feet, and Mays returned it to the infield after the catch before either runner could take a base. Arms don't get stronger than that.
However, as to what I personally saw in my life- Dwight Evans takes the cake by a mile.