LEGO brick competitors? I'm trying to find all the competitors to LEGO. I know there is MegaBloks. What are some more?

The base idea is that they should be bricks and they need to connect to each other like LEGO. However, it does not need to be compatible with LEGO.

Also open source designs are always welcome!
Mega Bloks: the well-known Canadian brand
Oxford toys - review
Hasbro KRE-O
K'Nex - yes, they do bricks too (not sure about compatibility though)
Cobi
Best-Lock
Character Building from The Character Group, a range of licensed products including Dr Who, Deadly 60, HM Armed Forces and Ben 10 to name a few. 


Disclaimer: some of these retrieved from the lugnet off-topic/clone-brands group; they also mention "Art Asylum’s C3 Brand" but the site doesn't seem to work.