I've liked this show for a while.
Billy, a plain stupid little boy, and Mandy, a cynical girl trick the Grim Reaper into being their friend forever. They go through many supernatural adventures and all that stuff. This show makes evil funny.
The humor can go in between. Sometimes it's just hysterical, and there are many adult jokes as well. The potty humor can be a bit overused, though.
They also don't repeat new episodes enough, blah. Heard it was getting scrapped this year (ew)..
Anyway, This show brings back some of what was lost in the transition between 90's cartoons and this decade's cartoons. Really gives you a break from the cruddy shows they have now.