C++, 286 284 236 bytes
Now with extra golf!
#include<iostream>
int main(){char a[]="#include<iostream>%sint main(){char a[]=%s%s%s,b[]=%s%s%s%s,c[]=%s%sn%s,d[]=%s%s%s%s;printf(a,c,b,a,b,b,d,b,b,b,d,b,b,d,d,b);}",b[]="\"",c[]="\n",d[]="\\";printf(a,c,b,a,b,b,d,b,b,b,d,b,b,d,d,b);}
I'm currently learning C++, and thought "Hey, I should make a quine in it to see how much I know!" 40 minutes later, I have this, a full 64 114 bytes shorter than the current onethe current one. I compiled it as:
g++ quine.cpp
Output and running:
C:\Users\Conor O'Brien\Documents\Programming\cpp
λ g++ quine.cpp & a
#include<iostream>
int main(){char a[]="#include<iostream>%sint main(){char a[]=%s%s%s,b[]=%s%s%s%s,c[]=%s%sn%s,d[]=%s%s%s%s;printf(a,c,b,a,b,b,d,b,b,b,d,b,b,d,d,b);}",b[]="\"",c[]="\n",d[]="\\";printf(a,c,b,a,b,b,d,b,b,b,d,b,b,d,d,b);}