It's always Lego, Lego, Lego around here. Lego this, Lego that, Lego movie projector, Lego-ish Daleks. Other construction toys barely rate a mention.
Even the stuff that looks like Meccano sometimes turns out to be Lego.
So here's an operational skeeball machine made entirely out of K'Nex (if you don't count some paper and rubber bands).