Why the Beech 1900? Well first of all because of the wonderful visual model of PDMG's bird. It comes with loads of detail, wonderful sounds and a nice flight model. On top of that, you can download masses of liveries from their site.
Secondly, because I want to be able to fly by hand. Again, glass cockpit technology is very nice, but at the end of the day, I could never believe myself to be a Boeing pilot (although I haven't had a crash for 3 years in FS). But if I would go for my PPL license, and then continue a little bit with IFR and twin engines, I could learn to fly a King Air, and the beech 1900 is a modified King Air. Thus, I could make myself believe that it's possible.
Anyway, the layout of the cockpit of the Beech 1900 also allows to have most of the commands (flips and switches) on the front panel, which allows me to build a table version of the cockpit. And that is because of the 3rd hard decision you have to make: space concession.

You can download this wonderfull plane at PDMG's website, at the price of 14.95 $.

I only use it for the visual model and the AIR-file, because I have my own panel, but I can assure you that even for those of you who don't have a cockpit setup, the VC of this plane is outstanding.

It comes with a wonderfull turboprop rumble noise, and for the moment this is my choice.