I've noticed myself making a couple of actions repeatedly and thought I'd share:
1) Add sorting to Subscriber Lists
In the reports section I can easily sort the results by any of the column headers. In Manage Subscribers, it is not possible to sort by column header. While this is probably unnecessary for clients with few lists, when working with clients that are uploading new lists weekly, it would be helpful to be able to sort the lists by Date Created, and Number of Subscribers.
2) Allow us to select whether a custom field should be visible in the preference center while we are importing that field
I've noticed that for several clients, each time I import lists with custom fields that shouldn't be seen by the email recipients I have to then remember to go into the custom fields management section, select the small edit button next to each field I do not want displayed, and then uncheck it. It could be helpful if, when importing these fields there was a small checkbox that allowed us to determine whether it was seen in the preference center or not.