This is a unofficial map of the Milky Way as shown on the Mass Effect, Mass Effect 2 and Mass Effect 3 games. I think it's pretty accurate, but may contain errors.
Only the Citadel and Alliance symbols are official.
December 16, 2011 update: I've had to remade the entire map due a lost of all the content of my external Hard Drive, so I took the opportunity to remove the frontier which caused a little bit of controversy.
January 3, 2012 update: Added the Reapers at the low left corner. They are not in scale, of course. On another way, the wouldn't be seen.
March 17, 2012 update: Added the Mass Effect 3 clusters and nebulas. Reapers erased. They are not comming anymore, because they are here...
September 3, 2012 update: Added the Mass Effect 3: Leviathan systems.
Semtember 23, 2012 update: The symbol of the Terminus Systems has been changed to the Omega's symbol, as it is the Terminus System the facto capital. Some clusters and nebulas wrongly place on Terminus have been changed to the Attican Traverse. Also I added a symbol indicating where is the homeworld of the major species.