FSX

FSX Add-Ons (archived, as I have moved to Microsoft Flight Simulator 2020 and DCS... stay tuned...)
Just as with the book page, here I would like to share recommendations for oustanding add-ons for Flight Simulator X (FSX) that I have come across over the years. All of these I can recommend without any restrictions.

Aircraft
PMDG 737NGX (and the -600/-700 expansion)
PMDG 747-400 Queen of the Skies II
PMDG 777 (and the -300ER expansion)
FSLabs A320-X
Majestic Dash 8 Q400
A2A Cessna 172 (incl. AccuSim)
A2A Civilian Mustang P51 (and the AccuSim expansion)
Aerosoft BN2 Islander
Aerosoft DHC6 Twin Otter Extended
Aerosoft Piper Cheyenne
Carenado Grand Caravan
Carenado King AirB200
Carenado Bonanza A36

Scenery
Orbx FTX - every package
FlyTampa - every package
Aerosoft Mega Airports - every package

Tools
PFPX flight planner
FSGRW weather
REX textures
Ultimate Traffic

Links
Some links with excellent, helpful material:

Freeware Aircraft
Dino Cattaneo (excellent F14, Goshawk, F35 etc.)
Ant's Airplanes (most notably the outstanding Tiger Moth and T-28A Trojan)

Freeware Scenery
FSX Freeware scenery list

Charts
Skyvector
VATSIM Pilot Resource Center

Weather
NOAA Aviation weather METARs/TAFs
Weathercharts.org

Tuning
Bojote's Tweaking and Tuning Tool
Nick's bible

News Websites
Simflight.de
Flusinews.de
Simflight.com
Avsim.com
Flightsim.com

Misc
Airliners.net
FlightAware
Flightradar24

Other Sims
Condor - the competition soaring sim (excellent soaring sim)
IL2 Sturmovik - Cliffs of Dover (buggy, yet amazing Battle of Britain sim)
Digital Combat Simulator World (visually the best sim engine I currently know)