I haven't found an airliner yet that is really the mutt's nuts. In my opinion, X-Plane standouts are the lighter aircraft like the BK 117, the Mu-2, and the newer Carenado general aviation releases. While there are some airliners in the works for X-Plane, I wouldn't expect Level D type accuracy yet from X-Plane developers.
The airfields (as you've noticed) are all fairly generic. There are some good freeware scenery conversions out there for X-Plane, but really X-Plane is lagging behind FSX when one looks at comparative scenery for FSX such as Manhattan X or the Orbx sceneries.
If you haven't visited already, X-Plane.org is the best place to find downloads (planes, utilities, and scenery):
www.x-plane.orgGood luck!