Reds:
Joe Price (55) -According to Baseballreference.com, his most-similar comp at age 23 is Travis Wood, and although Joe was a tall guy, I guess they are similar pitchers.
Pedro Martinez (43) -This is the "Bad Pedro Martinez", as he proved in '96 and '97 witht he Reds.
Others:
Mariano Rivera (42) -The greatest reliever of all time, and the only Yankee I find it impossible to dislike.
Howard Johnson (51) _As I recall, he came out of retirement briefly this year to play in an indy league game with his son. I don't remember the details; I think it was posted here.
Mike Easler (61) -The "Hit Man"; after his ML career he played in Japan and then with the Senior League's West Palm Beach Tropics. That must have been a fun team; besides Easler it included Dave Kingman, Rollie Fingers, Mickey Rivers, and Will McEnaney.
Bill Freehan (70) -Ever notice how odd-numbered decades produce many more exceptional catchers than even-numbered decades? In the 1930s there was Dickey, Cochrane, Hartnett, and Josh Gibson. The nobody too exciting in the 1940s. In the '50s we had Berra and Campy, among others, and in the '70s Bench was in his heyday alomg with Fisk and Simmons. Anyway, Freehan was by far the best catcher of the '60s, unless you consider Bench a '60s guy. By this theory, Devin Mesoraco should be really good.
Minnie Minoso (86) -Second-oldest player to have a base hit in the majors (Jim O'Rourke was the oldest, in 1904). Probably would have been a hall-of-famer if he'd been allowed to cross the color line earlier; might be one anyway.