I'm a big fan of both the superflash and Spokelits. Nothing like being lit up like a Christmas tree for night riding during the holiday season.

The lowest price I've seen on the Spokelits is here for $5.99 each. Shipping is $4.95, but doesn't seem to go up if you buy a bunch of them at once. So if you want to buy a pair for yourself ($11.98 + $4.95) while you're buying a pair as a gift for someone, the shipping on the second pair is basically free. I bought mine here and got them pretty fast.

Edit: On Saturday December 13, the price of a Spokelit had increased to $7.95 on the website I included above. The price seems to vary from time to time. Keep checking back to see if the price drops again.