My sewing table is littered with these right now; Chechoslovokian glass buttons:
A local bead store bought boxes full of these buttons in bulk. However, to find matching sets you have to dig. And dig. And dig. I spent an hour unearthing these ones, and my eyes were starting to cross. Eventually I narrowed down the piles I had chosen to these four, but I hope to go back soon for more!
These are the four different patterns I chose. The big one in the back you will see in use very soon!