jesskitten: Hmmmmmmm, hard to quantify just 3-5 out of my music library, especially since I've already edited the post a couple times to change out songs *snicker*.
Actually it may not be that difficult if you truly love music. The reason? You probably would have found at least 1 or 2 song that speak to you on a level no other song can match. For example, my favourite song of all time is easily Let Down by Radiohead. I have listened to it thousands of times now and it always manage to grab my full attention for the entire song. Also, the last minute and half or so still make me tear up every time I hear it. THAT is when you know you've got something special, and it's the reason why I can definitely claim it to be my favourite song ever.
I have connections with a few other songs as well for similar reasons (but nowhere near as powerful as my connection to Let Down), so maybe it's difficult for you is because you haven't found those right songs yet :).