I've used most of the RC sims and for me Aerofly has always been the best in terms of its flight characteristics and graphics. The relatively new RC7 Ultimate version (which I upgraded to from AF Pro Deluxe) really is a step up. Enjoying it over long cold wet weekends.
http://www.youtube.com/watch?v=7pvL_oVNzxY
http://www.youtube.com/watch?v=yqTFWhVrFYU
http://www.youtube.com/watch?v=Dmkpc7d9p_c
http://www.youtube.com/watch?v=ExPk7ej_fIU