What’s the best online brain training? Your Advice?

I’ve been a big fan of Lumosity and recently bought Block Builders to help with my spatial relations, but maybe there’s something better.  I have an occupational therapy assessment drivers assessment coming up and I want to make sure I’ve done everything I can to ace it.

I read the AARP column that lists five different online programs and am wondering if anybody’s used these and, if so, what do you think? Good? Bad? Waste of time and $$$? (Given the cost of these, its more $$$ than ¢¢¢)

Here’s the list from AARP:

1. MindSparke - http://www.mindsparke.com/ 
2. Lumosity - http://www.lumosity.com/ 
3. PositScience - http://www.positscience.com/ 
4. Cogmed - http://www.cogmed.com/ 
5. NeuroActive - http://neuroactive.ca/EN/

Here’s a link to the AARP article: http://www.aarp.org/health/brain-health/info-12-2011/brain-games.html