I have been a Gmail user since its debut and have never looked back since I migrated from Hotmail so many years ago. But I still use Hotmail (now known as Outlook) and Yahoo Mail on occasion for trivial emailing and one of the great features that they offer is one-click actions for delete or move. As the mouse pointer rolls over the individual messages, action icons appear to the left of the titles allowing one to delete or move the messages. This is immensely helpful and it's something Gmail doesn't have.
In Gmail one either has to right-click each message for a menu to pop up and then choose an action like delete or archive, or click the checkbox to the left of the message and then select an action on the top menu. Both of these methods are not as convenient as having single-click action icons appear as one rolls over a message.
I think it's time for Google to introduce action icons in Gmail, at least as a Labs feature.