1. All the Ultimate Terrain packages - Europe, USA etc...
2. All the Ground Environment packages namely GEX Europe, Africa and Middle East and USA
3. FTX and ORBX products for any region possible, especially great for Australia (ORBX)
4. Pro-mesh packages especially for Germany and United Kingdom
5. Austria Pro - Nice annotation of the scenery for Austria
6. FSX Global adds a nice dimension to landscape feautures suck as Mountains, Hills etc...
7. REX Essential is a must - great addon for textures (Environment - Dusk, Dawn and many many more...)
8. FS Open Clouds generates the most realistic flying experience and it work great with REX Essential Textures
9. PMDG - Not Negotiable!!! - I have every PMDG aircraft and for realism you cannot go wrong
10. The latest My Traffic addon (2012) - great for AI aircraft, realistic schedules available - By far the best AI traffic program, I've tried them all!!
11. TSS Sounds for all my aircraft be it AI or default FSX aircraft, FSX lacks a realistic AI sound program but TSS seems to be the best (Turbine Sound Studio)
12. GSX - Ground Services X is great if you want to add realsim for loading of cargo and baggage (any aircraft at any airport)
12. FS Passengers X - a must for a realistic passenger simulation - GSX and FSPX work nicely when configurated together
13. 3D Lights Redux - Not negotiable, adds great lights to your aircraft and AI aircraft, needs a little tweaking though especiall with the panel.cfg file