What's your favorite building toy?

[Static-Pulse]

As the title asks, what's your favorite building toy? Or if not favorite, what are you into these days?

I'm a life-long (since 5) LEGO maniac, with off-brands mixed in. However, for the last year or so, I've really been enjoying the younger kids' toy TRIO. They're a hair more complex than DUPLO (which isn't saying much), but they click with me. Lately, I've been getting more and more into K'nex as well. LEGO is still probably my favorite, but TRIO is a close second.

[domu]

Glyos from Onell Design is my current favorite.
http://onelldesign.blogspot.com/
A really terrific product and run by one of the genuinely nicest guys around.