His best work is scattered in short pieces of different types: Perhaps the most striking is the 'Frost Scene', or Cold Genius's aria from King Arthur - I heard this done live when I was about 16 years old, knowing nothing about it in advance, and could hardly believe my ears (listen to this version - don't watch it! - lyrics are below) :
What power art thou, who from below,
Hast made me rise unwillingly and slow,
From beds of everlasting snow?
See'st thou not how stiff and wondrous old,
Far, far unfit to bear the bitter cold,
I can scarcely move or draw my breath;
Let me, let me freeze again to death.
The music rises and thaws, then descends and re-freezes.
(Note - This was written for a dark-voiced bass singer, but nowadays is often done an octave higher by a counter-tenor - ie. the highest male voice. This is certainly effective, in its way - but in context the bass works better.)
Purcell was himself buried in Westminster Abbey to the lovely music he wrote for the funeral of Queen Mary - a popular (co-) monarch.
This is longish - listen, if you are short of time, just to the introductory brass and tympani fanfares and a little of the choral section. Sublime...
Perhaps Purcell's most enjoyable longer piece is his Come ye Sons of Art which has many delightful pieces - the most famous is Sound the Trumpet for two counter tenors - this comes at 6 minute on this recording. Purcell was himself a counter tenor, and wrote superbly for the voice.
Finally, here is my favourite of Purcell's songs - Music for a while - done by Kathleen Battle accompanied on piano.
(Note: As a rule, the best composers can be performed effectively using a variety of arrangements - it would be tragic if Purcell were confined to the ghetto of 'original instrument' performances.)
Notice from this that Purcell was probably THE best ever English composer at setting words to music, even banal words - which they often were, in a way that lies naturally both in musical and linguistic terms; and also his very characteristic use of a 'ground', or harmonically repeating bass; many of his very best works use this device.