In all fairness few things deserve a huge middle finger more than the educational system.
And brain training games are not educational games are not those little cartridges you can get for your DS that teach you French (est-que vous voulez francais?)
Me, I am 100% for all of them. They fill a market gap and further expand the undernourished and much maligned culture of gaming. True, the whole French learning thing turns a gaming device into a text book, but whatever, it's not like they are actually competing with anything and it is about as offensive to the educational system as a franchise book-store.
I find Brain Age amusing, it serves up a daily dose of clever little mini-games that are clever enough not to try to pretend to be anything other than clever little mini games, you aren't fishing in a world of ice spells and hobbits for a new armor upgrade, you aren't trying to foil an alarm system, you're adding. And if you suck, it just tells you.
As for actual educational games. How I long for the days of Number Munchers or Where in the World is Carmen Sandiego (not that recent action / adventure PS2 idiotness) when I was a kid Carmen taught me about the world and socio-political-economics in an exaggerated cartoon world of mystery. A later installment through a time machine in which added historical events to the mix (and proceeded to make the game way too hard for an eleven year old). And this made school more entertaining and fun for me, social studies became a strategy guide, and much to the school systems dismay, I began to earn better grades.
There are not many actual titles like the latter anymore. The most recent I can remember is the degree to which I learned about human Cell structure from Parasite Eve on the PS1.