We've used Prodigy but he plays it when he wants to. In the summer we use workbooks, and he learns very quickly (although he hates memorizing facts and prefers to simply work them out). He's very interested in rocks and gems, space and building things. He started building adult lego sets when he was 5 and now we try to get him different types of building material so he can make robots and structures. He also loves different kinds of puzzles, especially 3D puzzles. He loves reading but mainly about non-fiction (although he does like bunnicula and stick dog). He also loves flowers and plants, and enjoys growing vegetables.
He wasn't an early talker or an early reader, so there's always been a big "if" about his educational needs. We've arranged private testing with a psychiatrist, although that won't happen until December. One thing I've already seen is that he feels bad about not being able to write as easily as other kids, and it worries me that he will only see the problems and not the things he's good at. We've already seen that some already, and it's not something I want him to grow up believing.