For myself, it has to be the '57. The distinctive sculpted nose (the '87 will be a close second in terms of styling), the mechanical simplicity (not everything has to have a $#%@en wire attached to it), the handling characteristics (well, during high speed taxiing that is), the excellent mtce documentation (mm,ipc,srm clear and uncomplicated) and it never broke (compared to others) and lets not forget the mindboggling bags of power strapped under it (hence the HIGH, in high speed taxiing). Granted, I haven't touched one in almost three years, so I'm yammering on about it from memory. But nice memories nonetheless. The Tristar, however, provided many, many hours of instructional hands-on learning. It had grace in the air that no other could compare.