Some
UPDATES! 19/09/2014
Just one new country, airport stop-over with just a walk outside aiprot terminal and I've been again on some of them!!
I'm from Italy, so:

Italy

France (1986, 1990, 1991, 1998, 2000, 2001, 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2013, 2014, 2015)

Monaco (1986, 2001, 2007, 2008, 2009, 2011)

Switzerland (1987, 1999, 2001, 2004, 2007, 2009, 2010,
2012, 2014)

United Kingdom (England & Scotland) (1996, 2004, 2008, 2010x2, 2011)

Ireland (1997)

Liechtenstein (1999)

Austria (1999, 2004, 2005, 2006, 2007, 2008, 2014, 2015)

Israel (2000, 2006, 2007)

Vaticano (Holy See) (2000, 2005, 2008, 2014)

Spain (2001, 2005, 2006, 2009, 2010x2, 2013)

Greece (2001, 2007, 2012)

Slovenia (2001, 2007, 2011, 2013,
2014)

Nederlands (2001, 2005, 2006, 2007)

Germany (2001, 2002, 2004, 2005, 2006, 2007, 2008x2, 2009x2, 2010,
2011,
2012,
2013, 2014, 2015)

San Marino (2003)

Finland (2003, 2008)

Estonia (2003)

Sweden (2004)

Denmark (2004)

Portugal (2005, 2014)

Belgium (2006)

Luxemburg (2006)

United States, to be more precise CA, NV, UT, AZ (2006) and NY, NJ, NV, CA (2011)

Czech Republic (2006)

Hungary (2007)

Bulgaria (2007)

Kuwait (2007x2, 2009x2, 2010, 2012)

Oman (2007)

United Arab Emirates (2007x2,
2009, 2010, 2013)

Qatar (2007,
2010,
2012)

Russia (2008, 2011x2)

Saudi Arabia (2008)

Jordan (2008, 2009)

Romania (2008x2, 2009, 2011, 2013, 2014)

Malta (2008, 2012)

Poland (2008, 2010, 2013)

Tunisia (2008)

China (2008, 2009, 2011x3, 2013)

Morocco (2009x2, 2010)

Iran (2009)

Croatia (2009, 2011, 2014x2)

Nigeria (2010)

Turkey (2010, 2012, 2014)
Gibraltar (2010)
French Polynesia (2011)
Hong Kong (2011x3)
Macau (2011)

Taiwan (2011)
Brazil (2012) only stopover

Chile (2012, 2014x2)

Cyprus (2012)
Akrotiri British Sovreign Base (2012)
Turkish Republic of Northern Cyprus (2012)

India (2012, 2013, 2014x3)

Andorra (2013)
UPDATE +2
Palestine (2000) [I don't know why I always forgot to put it here...]
Argentina (2014) only stopover
So
51+6+1 as a whole! (counting Gibraltar, Palestine, Hong Kong, Macau, French Polynesia and British Sovreign Base as special regions; Nothern Cyprus quoted as extra) and including both Brasil and Argentina which are just flight stopovers