What a macabre question...and yet somehow...
My trouble is this, I don't have one song, I have many. In fact, I've even contemplated making a mix tape AND doing commentary - that's right folks, he wants to DJ his own funeral and/or wake. Posthumously, no less! Just picture - my disembodied voice, yakking about some song and why it means so much while friends and family are forced to listen...hellooo therapy for the loved ones.
Okay, okay, maybe the commentary part is a bad idea...but, BUT the mix tape idea..
Now to narrow it down for the purposes of this challenge, I'd have to go with the Golden Slumbers trilogy off of Abbey Road (Golden Slumbers/Carry That Weight/The End)
http://www.youtube.com/watch?v=2qP4Ye15J0Y&playnext=1&list=PLC26E4F8ED170D711 There's just something that is very comforting about that whole song cycle and I like the message that "the love you make is equal to the love you take".
And yes, I'd definitely throw in "Her Majesty" because it reflects my humorous side, and as a way to make people laugh a little during what I'm assuming would be a sad time. Such is me. :)