There are many good sceneries for those areas for FsX depending on what kind of flying you like doing, low and slow or airliner or both.
For freeware have a look at:
For payware one site is the FsPilotshop:
Here there are many airport and city sceneries. Some larger sceneries more like Orbx include the aerosoft VFR Germany series which unfortunately are quite expensive and the Switzerland X package which is ridiculously expensive.
If you're interested in the UK then there is good payware photoreal scenery and airports too although buying the whole country might be expensive:
The only places I've really done sim flying in the Middle East is Turkey and Israel and Saudi Arabia. There is some pretty good freeware airport sceneries for all these areas in Fs9 but I haven't tried in FsX.
Hope it might help.
Tyrion,if you like flying in the Caribbean I can recommend Paul Wheeler's freeware PWSceneries available at www.strikingsoftware.com
It is 5 seperate volumnes covering Grenada,St.Vincent and Barbados,St.Lucia and Martinque,Dominica and Guadloupe,he also offers photo real reefs and replacement sand textures for the coastlines,If you want to see them in the sim,I recently did a post in the screenshot forum called "Caribbean Cargo Run" using these packages.