How can I maximize Wasabi flavor? A few months ago, I went to dinner with my brother-in-law, and he introduced me to Sushi. I was skeptical (I've gone nearly 40 years without trying it), but I enjoyed it. My favorite part, however, was the Wasabi. It's like horseradish but hotter.

I can tolerate very hot foods, but I don't like the lingering afterburn. This is why I've taken a liking to Wasabi - it is hot, but without the afterburn. 

I found a tube of Wasabi at my local Piggly Wiggly, it's basically the same stuff they had at the sushi place. However, after a few weeks of putting it on crackers, pita chips, and carrots, I've developed a bit of a tolerance and, as a whole, I don't feel that it's providing enough hot. I would prefer more.

I found on-line that they have Wasabi powder, but I'm not sure if it will be very hot or not. Also, I'm not sure how to make a dip from it.

How can I maximize the Wasabi flavor? Is there a "pure" Wasabi flavor I can buy? Is there a "nuclear hot sauce" made with Wasabi?
Prepared wasabi that you can buy in a common grocery store (both powdered and paste) is basically just horseradish with green dye in it. Really, you've acquired a taste for horseradish. Not that there's anything wrong with that! I would recommend seeking out other horseradish-based sauces and condiments. You'll probably enjoy them better than the fake wasabi.

If you're interested in finding real wasabi, you'll need to look for it in a specialty grocery store (or online). It's traditionally prepared by grating the fresh root on a sharkskin grater. However, what you had with your sushi was most likely the fake stuff, unless you were in Japan or a very high-end sushi restaurant here in the states.