I'm biased, so I'll tout the 99E300turbodiesel as a fantastic car. My opinion has become much more favorable the longer I drive the car. We just got back to Fort Worth after tanking up on Cerrillos road in Santa Fe--made it all the way back, 624 miles with fuel to spare. The car got 37.5 MPG at speeds of
70 to 80. The 98 and 99 have loads of power to spare due to the turbo, but you will pprobably get better mileage around town with the 96 and 97 non-turbo. I get 27 to 30 depending on how I drive.

As far as reliability goes, I think it comes down to finding a good tech who cares about you as a customer. Many of the quality issues seem related to repeat repairs or damage caused by improper repair methods. With all the electronics its pretty much a crap shoot, but so far I've been lucky, needing
only one MAF sensor and a fuel temp sensor. Many have complained about glow plugs not lasting and light bulbs burning out, but so far, so good for me.

Steve