I've had to make this decision a number of times and I've always gone for a higher salary (a bird in the hand is better than two in the bush, or so they say). What do you think?
It depends on your personal preferences and risk tolerance (and a lot of other things). If you're talking about "a bird in hand," then my guess is that you prefer things to be more certain. In which case, higher salary sounds like it would make you happier.
Here's how I generally look at this type of situation: What salary do I need to not have to worry about salary? In other words, at what point does my salary put me close to an equilibrium with my spending. Once that's covered, each incremental dollar of salary doesn't have much of a real impact on my life. Above that point, I become more interested in equity than salary because the equity (if it pans out) could have a much larger impact on my life.
Hope that helps!