Sputnik 1 was a shiny metal sphere, as were it's immediate followers.
These days Earth satellites are generally rectangular prisms, either one or a few stuck together. Basically big metal chassis chock-full of electronics and instruments in rack-like structures, with solar panels and antennas as appendages, fixed or deployed.
But there have been many Earth satellites that were cylindrical in shape.
Many (if not most) were spin stabilized around the cylinder's axis and covered in solar cells roughly uniformly.
Question: What was the first cylindrical Earth satellite to be launched? What was the last?
Example of a cylindrical Earth satellite covered in solar cells:
View of the AUSSAT-1 (now Optus A1) satellite after deployment on STS-51-I. Australia's AUSSAT communications satellite is deployed from the payload bay of the Shuttle Discovery. A portion of the cloudy surface of the earth can be seen to the left of the frame. Date: 27 August 1985