1) Blizzard of 78 (I was 10 and school was cancelled for a week!)
2) April Fool s 97 (Awesomeness!)
3) January 2005 Blizzard (30"+ in Cambridge)
4) October 2011 Snow Storm (Freak storm)
5) Hurricane Irene (Western New England flooding was surreal)
Runner up: Feb 2013
I've had several personal severe weather episodes that have been personally mind blowing but were isolated so I went with the historic stuff.