I've been putting off doing the Main quest since I don't like how it looks when the gates have been closed. So my question is after you beat the game and close the last gate does the land still looked messed up from the closed gates, Or do things return to normal?

From what I remember its been awhile since I did the MQ, but the gates all close leaving the stumps?.
Imperial city regenerates I think, but Kvatch does not.
So apart from open world remains of gates it all goes back to normal.

Madocmayhem is correct. All Oblivion Gates close, leaving behind their stumps and whatever Oblivion plants might have grown up around them (and perhaps a few Daedra). The Imperial City goes back to more or less normal aside from the Temple being destroyed and a big stone dragon in the middle of it.

That kind of svcks. I've been putting off doing the main quest for so long because I didn't like how the gates made the land look when I was playing on the 360. I never beat the game. I got close to the end but stopped playing when I got my game computer and learned about all the awesome mods out.

I know there's at least one mod that restores the Temple District, but I'm not sure about removing what's left of the gates.