A few:

- being able to mange banking while traveling internationally (or to a state/province that does't have a branch)

- 30 second transfers between accounts (or to other banks)

- few minutes to open a new account

- see posted (and pending) charges within a day or two instead of a month (I regularly import for my budgeting software)

I'm a developer and actually do consider myself a little bit of a luddite. But online banking is helpful to me over traditional banking.