Pam asked about Quadrilla in my last post. They make wooden marble runs. Daniel and Anya got the "Try-Me" set for Christmas, and Daniel liked it so much we got him an extension set for his birthday. They are a European company (German, maybe?), and the marble runs have sturdy, good-quality wooden pieces. Daniel has been playing with his marble set (as he calls it) pretty much non-stop since he opened it up after his party on Saturday. (We knew if he opened his present before the party he would want to play with it instead of his friends, so we waited until afterwards.)
I'm one of those people who would rather have a few good toys around than lots and lots of cheap plastic crap. Our very small house makes this a necessity. In any case, high-quality building toys (like the marble set, the train set, the blocks) are things we'll keep around even after our kids have outgrown them. The little plastic toy guitar that lights up and plays the same annoying twangy country-esque tune when you push the purple buttons...well, that one is a favorite toy, too, but I personally won't be sad when it leaves the house.
Anyway, here's a little video I took of the marble set in action. (Sidebar: I was using the new little camera Stuart got me for Christmas that I lovelovelove. Also, I have never tried uploading a video on Blogger before, so it might take me a couple tries. Bear with me.) You see Anya rocking in the background; I think she was dancing to the U2 CD Daniel turned on before we put the marble run together.