Redesigning my site, and not sure what is best for seo, subfolders or direct .html links?

[hoodamath]

,I have 4 examples to choose from, what is best:?

http://hoodamath.com/games/dublox/index.html

http://hoodamath.com/games/dublox.html

http://hoodamath.com/dublox/index.html

http://hoodamath.com/dublox.html

[Highland]

Is Dublox a category of products or just a single product?

If it's a single product I would use http://hoodamath.com/dublox.html

If it's a category I would use http://hoodamath.com/dublox/index.html