Here's mine, which does an ASCII mandelbrot, written as an ASCII mandelbrot, in C.


 int main(int argc, char* argv[]){ unsigned
 char c='r';double x1,y,y1,t=0,q=78,r=22,x,
 x2,y2,a,b,v;do{(c=='r')?(y2=-(y1=-1.6),x1=
 -2.0f,x2=0.8):(c=='?')? c=0, printf("%f\
 ,%f:%f,%f",x1,y1,x2,y2):(c <':'&&c>48)
 ?x=x1,y=y1,*(c>'3'&&c<':' ?&y1: &t)
 +=(y2-y1)/3,*(c>'6'&&c< ':'?&y1
 :&t)+=(y2-y1)/3, *((c == '8'
 ||c+3=='8'||c+3 +3== '8'?&x1
 :&t))+=(x2-x1 )/ 3,*((c
 =='9'||c+3== '9'||c
 +6=='9' ?&x1: &t)
 )+=2*(x2-x1) /3,x2=
 x1+(x2-x)/3, y2 =y1+(
 y2-y)/3:(c=0);for(y= y2;y>=
 y1&&c;c=1,y-=(y2-y1)/r, putchar
 ('\n')) for(x=x1;x<=x2; x+=(x2-
 x1)/q){a=b=c=0; while ( ++c&&(a=(t
 =a)*a)<4&&(v=b*b)<4)a-=v-x ,b=y+b*2*t;
 putchar("#@XMW*N&KPBQYKG$R" "STEEVxHOUV"
 "CT()[]%JL={}eou?/\\|Ili+~<>_-^\"!;:`,. "[
 c?c>>2:63]);}} while((c=getchar ())!='x');
 return 0;/* Mandelbrot - S.Goodwin.2001*/}


Originally posted here http://marquisdegeek.com/rnd_obs.php