For those of you who don't know, Steeplechase refers to horse racing (those little hurdles the horses jump are called steeples) and the artwork Sears chose reflects this.  The picture is rather well done, and makes the game look far more exciting than it actually is.  The woman pictured in the artwork was a secretary in the engineering department who was chosen to be in the picture because she just happened to own her own horse.  The name of the horse was Pandora.
As Steeplechase was a Sears exclusive the Atari artwork was never released.  However thanks to Tim Lapetinoís fantastic Art of Atari book, we can now see the original Atari artwork which features more horses and no steeples.  The Atari version was going to feature that blurry motion style which was common in early 2600 artwork.  However it also has a really large jockey head at the bottom which is kind of off putting to me for some reason.  Interestingly neither artist decided to copy the trippy arcade cabinet artwork which featured an odd cartoon horse blowing out multicolored smoke.  I wonder why?
Itís close, but letís give Sears the win here because Pandora is an awesome name for a horse!