Collide by Howie Day.
I love this song for a lot of reasons, the foremost being that it happens to fall decently within my vocal range. Besides being rather complimentary (I think) to my limited vocal range though, I also enjoy this song for its reflective tone and interesting lyrics. I got into introspective acoustic music when I was in high school, and its a love that I've never gotten over.
I think this song, and others like it, influenced a lot of what I still listen to today and even how I write lyrics, so it seemed like a natural fit for what song I was deciding on covering next.