I believe that the best game for your child is one that you make yourself. After all, who knows him better than you? There are many nice educational games available on the market, I have even sold some that I have made. However, I recommend MAKING games rather than buying games, even mine!! Let me tell you why...
1. A game made specifically for a child meets his exact needs at this moment. I could make a reading game (and I have made LOTS of reading games) but it might not drill the exact skills that your daughter is needing practice on. If YOU were to make a similar game, it would not meet the needs of your neighbor's child who is at just a slightly different place then your child. The game you make would, however, be exactly what your son needs.
2. There are many different formats (styles) of games. There are card games, bingo, board games, active games, self-correcting games, speed games, and on and on. Some children prefer one or two types of games to others. So you can choose the format of play that your child enjoys.
3. Themes of games is really the DECORATION. For a racing fan, I would create a board game with a race car design. Now the "ballerina" that lives in my granddaughter would prefer a board with pretty stickers of little girls dancing on their toes or princesses or fairies. Knights, castles, dragons, or pirates would thrill some of my grandsons. Another grandson would love things decorated with stickers to match Disney's Cars. So think about your child's interests and decorate: horses, Indians, dinosaurs, fast cars, American Girls, super heros...or think about the unit you are studying: insects, Africa, George Washington, bones, fractions, food groups, the flag, the Civil War, or whatever.
4. THE PRICE - Purchased games can cost LOTS of money. I know, I have priced them. I check them out and then make my own game. I have made over 1000 educational games that I have used with my children at home, in the classroom during the years I taught in a small Christian school, and now with my grandchildren. I could NEVER have begun to purchase that many games.
5. VERY SPECIALIZED - I had a boy in my classroom that was having difficulty distinguishing the difference in the sounds of short /e/ and short /i/. I made a game for him to play at home with his family. I couldn't have found such a game, and even if I could, I would never have been able to justify the cost for the needs of ONE child.
6. Children enjoy making the games too. Many years ago daughter made a VERY boring (in my opinion) game that drilled addition and subtraction facts. However, because she made the game, she was more than willing to play it, and who was I to complain about HOW she was drilling her facts. Now, her son Douglas has the same fun making games. I often let the children decorate different gameboards, and I provide the skill cards to use with them. They like playing their creations.
Home-made games make so much sense to me. We have had so much fun making and playing them. I hope that you might also find the benefits of them for your families.
WARNING: Game-making is addicting...LOL