Because lubricant is a product you're using on your body (and possibly others bodies) there's never going to be one answer to a question like this. So much depends on your preference and your body when it comes to finding the 'best' lube.
But there are lubes that you should never use with silicone toys, and those are any silicone-based lubricant. Silicone lubes destroy silicone toys, and they cause them to kind of "de-cure," making the surface all soft and squishy and unusable. So, now you know what not to use.
Beyond that, if you're trying to find the best lube for you, here are some tips on how to pick a sex-toy friendly lubricant. I always recommend starting with a small bottle of something, as you really won't know if you'll like something, or worse, react to something, until you try at least a little of it on your body.
