Songs 4 graduation?

I am in 5th grade and we are graduating this yr. We r going to sing a "farewell/ goodbye " song. we can bring in suggsestions.they hav 2 be approate tho... I want to bring some in but i cant think of any good songs to do. I have over 900 songs on my ipod and i cant find a good one!!! Help!!! the songs dont hav to be like slow or sad or have like goodbye or anything in them but it has to hav things like u kno ... with friendship,k memories... all that stuff!!! I cant think of any!!!HELP ME!!!