Can you give some examples of Gnome extensions you find useful? I tried perusing the list a few times but nothing really jumped out at me as a huge improvement.
It seems it's not really a popular opinion, but I also like Gnome Shell a fair bit. It just gets out of the way for the most part.
Sure. I started off by installing cairo-dock (pkg, not ext), a nice OSX-style autohiding dock (tweaks req'd). This allowed me to install Remove Activities Button[1] and Applications Menu[2], which combined to replace the rather useless and annoying Activities menu with a standard Gnome2-style applications menu, and get rid of the ugly dash that was stuck to the left of my screen, hogging real estate. This had the sanity-preserving side-effect of removing the stupid hot corner to Overview that I would accidentally trip every other time I tried to hit the back button in the browser. It can still be accessed with the Tux/Windows key. I also installed Force Quit[3], which puts a little 'x' next to the Applications menu. Click it, then click any misbehaving window to kill -9 all procs associated with it. Haven't had to use it, but it seems handy.
Next, I installed Brightness Control[4], as the fn+arrow keys don't work worth a damn, and Advanced Volume Mixer[5], which replaces the standard volume bar with a separate bar for each app. I installed Remove Accessibility[6], just to de-clutter, and All-in-One Places[7], to give me some handy shortcuts.
Quit Button[8] replaces the username "status" menu with the familiar options from Gnome2, and Settings Center[9] gives me quick and easy access to a variety of settings menus. Finally, Frippery Move Clock[10] puts the clock over in the top-right corner, where it belongs. I'll probably look into installing some workspace-related extensions as I become more comfortable with the system.
The combined result of these small changes is a system that I find far more friendly and usable. As I said above, the only thing I find wrong with Gnome3 is the defaults. Gnome Shell is incredibly extensible, and absolutely gorgeous. It now works for me like a cross between Gnome2 and OSX, with some handy extra features thrown in. Some of these changes are fairly major, while others are tiny tweaks, but I love how simple and easy they are to experiment and play with. Most changes are instant, and enabling/disabling extensions simply involves flipping a toggle switch on the extensions web page. I've only been running F17 for a week, so I'm sure I'll discover more changes to make the GUI just right.
It seems it's not really a popular opinion, but I also like Gnome Shell a fair bit. It just gets out of the way for the most part.