With the high residuals and subsidized leasing BMW offers, I always lease. I never want to continue driving a car by the time it is paid off and selling a used car is a total pain.
But, obviously everyone's personal financial situation will dictate what they do.
2016 F15 X5 3.5xdrive (Current) - 2013 535i xdrive (Gone)
2008 E92 M3 (Gone) - 2006 E90 325i (Gone)
2002 E46 325xi (Gone) - 1991 E30 325i (Gone)