Not sure about the yeast infections, but I don't use KY. I just got Ride H2O a few days ago and it's quickly becoming my favorite.

My favorite water based lubricant is definitely the one by Yes. The only trouble is you have to order it online as the seller is primarily in the UK. But it's totally natural, tastes and smells pleasant, and is the closest in feel to natural wetness I've been able to find. I hear similarly good things about their silicone lube but havent tried it.

I personally had some issues with both ky and astroglide. It was during a time when I had recently changed bc's, a change which apparently made me much more susceptible to infection because after changing it again, I don't have that problem anymore. Before finding Yes, I'd also tried Ride H20, a Sliquid product, and the Kama Sutra Classic Love Liquid. H20 and the Love Liquid were probably my favorite of those, and they can usually be found at most sex stores.