If price is not an issue, then the X5 is by far the superior choice. The other two SUV's are also very good, but they are not even in the same class as the X5.
The only SUV's that should be compared to the X5 are the Lexus RX350, Mercedes ML, Acura MDX, Audi Q5, Infiniti FX50.
The X5 is superior to your other two brands because it has luxury that the other two do not. One of the main things is the engine, where the X5 is unmatched in performance. It also has a nice navigation system in iDrive (some people hate it, some love it), good leather seating with side bolster support, 8-way adjustable seats and excellent blind spot visual. The material and build quality of the BMW is also very good, and it has a prestige about it.