The current setup
While a few previous notes outlined the benefits of various third party applications and add-ons, I have actually become frustrated by WindowShade for its bugs in the minimize in place feature, and the lack of updates for finderpop.
Currently I have settled on the following UI scheme:
Screen corners are set to Exposé triggers:

Contextual file/folder access: Folderglance. This would work well, but it can severely degrade right-click performance. Thus I no longer use it, and navigate via Quicksilver instead.
Window switching: Witch. I have Open-~ set to display a window dialog within-application, and Open-Option-~ to display the dialog of all currently open windows for all applications.
Virtual desktops: Virtue. Desktop switching is set with Control-Shift-Left Arrow and Control-Shift-Right Arrow, and the desktop overview switcher is shown using Option-Tab. Virtue shows promise but I wish the modal switcher behaved just like the application switcher brought up with Open-Tab. That is, when I hit the trigger I expect the focus to be placed on the next desktop, not to remain at the current desktop.

As for my most accessed folders, I keep them on the Desktop, as my Dock is hidden most of the time.
Launcher: Last but not least, Quicksilver is the clear leader here. I have it triggered with Open-Space, moving Spotlight to Open-Shift-Space.

Other items of interest
I have found MenuMeters to be indispensible. I usually just show CPU and memory load, and I change the color schemes to gray tones to minimize distractability.

I also keep iStat Nano running on Dashboard, along with a blank sticky note or two, the weather, and calendar.
