I know this sounds nerdy... but is there a "formula" for a great song?

What I mean is... what are some things that make good songs good songs? I have been having trouble with writing songs for a long time, I have written a few, but they never sound very good to me. I usually end up throwing them in the corner. I have enough heartache in my life to write good songs, but I guess I can't get it in a form to make a good song. So please any suggestions are welcome :)