I recommend the 1968 or so, EB editions if you are looking for an older one. The 1972 or 1973 was the last of the classic style ones, after that they went with Micropedia/Macropedia etc. which is not what you want.
The articles are well written, and if covering pre-20th century history, literature, or other topics, should still be excellent introductions.
I think the copy at my parents' house is about 1968. I remember when I was young and we got it. I guess I'll have to duke it out with my sister for who gets it!
The articles are well written, and if covering pre-20th century history, literature, or other topics, should still be excellent introductions.