This snowflake is a Jan Stawasz pattern done in Altin Basik 50 metallic gold.
This next one is a design by Robin Perfetti called First Snowfall. You can find this and all her other free patterns here.
Another beautiful pattern by Robin Perfetti is called "Design Tutorial Snowflake" and can be found from the above link. I think this is my favorite of her snowflakes.
And finally, we come to the last snowflake for today (but not for the season).
here. The onion rings in the center were a little tricky because I thought that the inner-most rings were thrown rings off the chain but they are not. All of the inner rings are tatted with shuttle one as the working shuttle. After a little fiddling, here's what I figured out. Start with one of the inner most rings, then turn that ring upside down and tat the outer ring (the one inside the onion skin) next. Then reverse work and tat the onion skin, joining at the intersection of the two rings. Do not reverse work and tat the little chain going to the next ring. Once I figured out that I don't need to switch shuttles, it was a piece of cake.