Ents were around next, but not as Ents, since the trees that they *were* had not been awakened by the elves as yet.

So we have two different rankings here, firstly who was in existance first and who was after, secondly, who attained sentience first and who was after.

I believe it would go something like this:

Who Existed First?
Tom Bombadil
The trees which became the Ents
Elves

Who achieved Sentience First?
Tom Bombadil
Elves
Ents that had been just trees

That's my penny's worth.

Cheers

Padster