At the funeral services I've seen so far, there are several songs played during it. At least here in Czech republic. But there are three pieces I would want to be played at my funeral.
First is 'Largo' from "From the New World" by Dvořák. First of all, it's an amazing piece, and second, when I was sill part of string orchestra here at local school of arts, we would play it, and it sounded absolutely amazing.
And the second is "Meditation from Thais" by Massenet. Another amazing piece, and also the piece I graduated with - once again when I was still playing violin. So - both the pieces so far hold something very dear to me.
And the last piece is a bit similar to your Always look on the bright side of life (which is amazingly hilarious piece - gotta love the humour) - it's named "Poslední štace" (Last gig), and it's about a circus that is not performing today, because yesterday their clown died and today is his funeral, and everyone is going to see him on his last journey. But nobody will be crying because the clown always liked laughter more. Of course, at the heavens gate even St Peter will be laughing, when the clown will trip and fall on his face, and all the souls in the heavens will laugh so hard they will cry - and their tears will change into rain falling down to the earth.
Which I think sums up quite nicely what my funeral should be like - some tears, some calm contemplating and then some parting laughs, because I may be gone physicaly, but I will always be there in the music they played on my own last journey. Not to mention, crying people always unnerved me, and like hell do I want to be unnerved on my own funeral O_o