Spoiler alert.

I thought the ending was a really nice unification of scientific and religious thought, done in a novel way that I've never really seen before. If you don't like it, then I guess there's no other way to really argue for the story. I always thought that Asimov's strength in writing lied in his ideas, as opposed to his descriptions and writing ability.

Quite simply it's the twist in the last line. With an Asimov short story, you expect a twist anyway that forces re-evaluation of the characters and events, but The Last Question manages to transcend this and forces the reader to re-evaluate the nature of the external world (ie. outside the story itself, with some inter-textuality to the Bible thrown in).

The execution of this idea was also first-rate, IMO. The question 'can entropy be reversed?' acts as a brilliant 'hook' for the story as he fleshes out the history of the universe. He took a question usually too remote to be worth consideration in literature, and humanized it. And finishing on the Genesis quote was a stroke of brilliance.

'It takes control and slowly tears you apart.'

The major themes here are ones that challenge us and are hard to cope with. Particularly the theme of inevitability. It is in the back of all of our minds and we condition ourselves to accept it, but it is always there. Asimov solves the inevitability of resource degradation by expansion and the inevitability of death by immortality, but in the end there are both, in fact, inevitable. When all seems lost and the bleakness of our existence is brought into scope, he presents the cyclic nature of time. A novel approach to a problem that plagues the core of our being. This is where the story really jumped from good to amazing for me. I'm still stuck on it.

The notion of the sun as the fundamental power source driving the earth was somewhat novel to me. I mean, we all know humanity wouldn't exist without the sun, but I hadn't thought of the stars as the batteries of the Universe before.