Here is my two cents:
Get a BMW and you will never want to drive other vehicles.
If you do want a X5 or X3, get a new one or a Certified Used one with extended warranty. You need to know X3 and X5 are made in US so quality is not comparable to BMW 3, 5 or 7 series sedan which are made in Germany. The repair costs could be sky-rocketing (I learned my lesson after the initial 4-year warranty expired).
Last, Get the sport package (no matter BMW sedan or SUVs) - it worth every penny of it.