Here is a great link that describes all the alignments, which planets were involved and the dates:
http://www.etsu.edu/physics/etsuobs/starprty/22099dgl/planalign.htm
Thanks a lot for that link, it's an excellent article.
An additional way to view these planetary alignments is provided by the
Planetary Aspects and Transits software. Here are images of the three alignments mentioned in that article:
Here is the alignment for February 5, 1962, showing a 5-stellium formed by the Sun, Mercury, Venus, Jupiter and the Moon:
Of the three, this is the closest alignment. The minimum average pairwise separations of the five planets (which you can find by moving back and forward by 30 minutes in the software) is 1°21' at 03:00 GMT on February 5.
Here is the alignment for May 9, 2000, showing a 5-stellium formed by the Sun, Mercury, Venus, Jupiter and Saturn:
The minimum average pairwise separations of the five planets is 4°14' at 20:00 GMT on May 9.
Here is the alignment for September 8, 2040, showing a 5-stellium formed by Mercury, Venus, Mars, Jupiter and Saturn. The Moon joins them so that from 08:30 GMT on September 8 to 04:30 GMT on September 9 there are actually six 5-stelliums (quite possibly a 6-stellium, but since these are so rare the software has not been written to detect them).
The minimum average pairwise separations of the five planets (other than the Moon) is 4°58' at midnight GMT on September 7-8.