Cunning Vixens, A Dark Concert And Much Glass.

''BEST of'' lists are approximate endeavors. I was sorry I couldn't attend the Mostly Mozart Festival's ''Don Giovanni,'' one of many tantalizing events I missed. But the following proved highlights of my year. 'CUNNING LITTLE VIXEN' A host of unusual creatures have appeared with Alan Gilbert and the New York Philharmonic recently. After the eye-popping characters of Gyorgy Ligeti's absurdist opera ''Le Grand Macabre'' last year came the whimsical creatures of Janacek's opera ''The Cunning Little Vixen'' in June. Mr. Gilbert conducted a vibrant performance of the score in Doug Fitch's enchanting production. [ABSTRACT FROM PUBLISHER]