I use water-based lube almost exclusively, since so many of my toys are silicone.
I used to really love System JO H2O, and still do, but lately I've been feeling that Sliquid H2O is the best for me. It dries up a bit faster, but JO dries a little bit sticky (dunno if I'm just noticing it more or whatever), while Sliquid doesn't. Plus, Sliquid lubes are very body-safe, while JO has glycerin and a ton of parabens.
Sliquid still can't top JO when it comes to flavored lubes, though.