Margaret Martonosi at Princeton runs a Great Moments in Computing Course where students read a through a number of papers that describe, well, great moments in computing.
The papers in it are all well-worth reading and are mostly accessible (with some effort) to a first-year grad student (i.e., anyone with an undergraduate degree in CS or something related.)
PS. Don't make the mistake of reading easy papers just because they're easy to read.
Link to a recent syllabus is here: http://mrmgroup.cs.princeton.edu/cos583/syllabusS15.pdf
The papers in it are all well-worth reading and are mostly accessible (with some effort) to a first-year grad student (i.e., anyone with an undergraduate degree in CS or something related.)
PS. Don't make the mistake of reading easy papers just because they're easy to read.