The best one was enlightenment DR16, but it has been discontinued.
It gave the option to remember the position of the first window per application and per a criteria you could set. Like "remember I want the Window titled Calendar from class calendar on the right of the screen".
Each theme would bring a set of different border styles and you could change them from the title bar menu and have it remember that. It was very easy to customize themes. The borders could have transparent sections, eg. your theme could have the window title in a bubble floating a few pixels away from the window.
Windows could be stickied, so when you switch virtual desktops, the calendar would follow.
It had pagers to show what's going on on other virtual desktops, so you could see when your downloads finished even if the program didn't use notifications.