MD-80 series is my vote, especially the MD-88.  You could ahve several off-shoots with this plane since it started out old school with dials and guages and end up with digital and FMC's.  I know there is 2 primary versions on the market, already but they are long in tooth and really not compatiable with Prepar3D.  PLus if you check, most virtual airlines have one or versions of these in their fleet... Just my 2-cents! ;)