Here's a list of some of the fun educational games we played listed by subjects w/possible links.  If you have any suggestions you want to add, just let me know!

ART
     History of Art    Masterpiece

GEOGRAPHY
     Brain Quest (Around the World)     Countries of the World     Risk

HISTORY
     Hail to the Chief     History of the United States     Your America

LANGUAGE
     Boggle     Quizmo (Phonetic / Sight Words / Vocabulary)     Scrabble

MATH
     Bazaar     Number Rings     Pick-It (Logic)     Quizmo (Add/Sub, Multiply/Divide, Fractions/Decimal, ect.)     Rack-o

SCIENCE
     Human Body   Earth Science     Into the Forrest     Space     Wonders of Science    The Way Things Work  

GREAT producers of Educational Games
  Ampersand Press     Discovery Toys     Professor Noggin's Card Games     University Games
     Kids.gov                    PBS Kids               Online Learning Games for Kids      Sheppard Learning