Serfas Seca RS. I've tried these, thickslicks, and whatever cambodian sweatshop tires come on eighthinch amelias.

Serfas Seca RS are light (under 200g apiece) and in the entire time I've ridden them I have not had one flat. They're nice and grippy too. Oh and what's best is they only cost about $30 and come in a ton of colors!