Willie Mays, Robinson Cano, Trevor Plouffe.
Nick Swisher NYY
Robin Yount - Milwaukee Brewers
Melvin Mora on the Baltimore Orioles is the only one that I know of.
Mookie Wilson
Anderson hernandez
Jose Reyes
According to http://www.cubsbythenumbers.com/cubs-all-time.html, no Cubs player has worn jersey number 66.
Meow and meower
Galen Fiss
Roosevelt Riley
Jose Reyes
lester borden