Who's the oldest?

[GildorInglorion]

Shelob should be pretty old, but she is just some kind of children of Ungoliant, the first giant spider that almost killed Morgoth and fled the Balrogs.
Fangorn must be older.

I think it's not beyond any reasonable doubt that Ungoliant ever died, but an implication that she in hunger ate herself!

And Bombadil a vala, no, I agree, that seems to far-fetched (is that an english word???, I mean something like very speculative...). The quote that Ulmo was the last to leave pretty much makes the case.