I couldn't possibly pick out the worst Broadway song ever. I don't think I've seen enough musicals to really be of help on that score. There are quite a few I hate, but I can usually see the value of them.
Calling "Send in the Clowns" the worst broadway song ever is completely absurd. If you don't like it, that's one thing. But it most certainly is not the worst.
Personally, I'm in the camp that likes "Little Lamb." I think it's pretty, simple, sweet, and sad and really works for Louise at that point in the show.
You promised me poems. ~Tricky