Face to face conversations [http://headrush.typepad.com/creating_passionate_users/2006/0...], bars, theaters, museums, entertainment parks, turist attractions, easy shopping posibilities, etc.

There are many advantages to clustering together that electronics and increased communication simply cannot replace yet (and I doubt it ever will, even video calling feels "phony" somehow).

The ability to find a group of people like you. If you're straight, white, and born in the small town, this isn't a problem. As a gay man, I'd have a lot of trouble in many small towns.

The ability to walk down the street at 3 in the morning and see a non-trivial number of people around.

A friend was in a small town teaching for the summer, and he said "So then we went to the bar. I say the bar because there was only one." Where I live, there are 171 listed in the phone book.

Mass transit precluding the need to own a motorized conveyance, proximity to life's staples (and the varieties available thereof), diversity in culture and ideas (even ethnicity, if that's your bag), architectural variety (nothing beats looking at a giant skyscraper for wondering at the sheer human achievement).

It's all subjective, after all; but that's just off the top of my head.