For example: Avant Window Navigator, Docky, DockBarX and Cairo dock.
I personally use AWN replacing both panels because:
- It has a tray area, so I can remove the panel (Docky didn't last time that I tried and was a no-go).
- Great performance (even in my netbook)
- Each applet is a different process, if one locks, AWN doesn't
- It's beautiful and highly customizable.
- Has a nice remember the milk applet, and loads of others (where loads > docky but loads < Cairo Dock).
- I can put it on the top or on the left of the screen (my petty favorites places).
- Last versions have Zeitgeist integration (icons display last and most used items)
- It works with python applets (fanboy disclaimer).
Anyway, I agree it's a highly subjective post and there is no such thing as a correct answer.
Personally I use Docky, which replaces the bottom panel containing active applications and such.
- I like the Mac/Win7-style mixing of shortcuts and active applications.
- I'm in love with the enhancements it can give icons (for example - displaying cover art, track length in place of the Rhythmbox icon).
- It has support for widgets although I haven't found many available for it except the built-in ones.
- The same can be said for themes, although I might not have looked hard enough.
- It's a simple, yet configurable dock that comes with several useful plugins and looks good out of the box.
Looking for more info on AWN, I found this article that compares AWN, Cairo Dock, and Docky. It may be of some help.
i'm using docky because it comes with pinguy os (ubuntu based) and i like how the icons jump to call your attention at certain specific moments, or how they jump if you click on them, i really don't know whats the best dock...i read that awn is better because lots of people dont want to use mono, and docky it has something related with mono, im trying in this moment awn, and i still prefer docky i hate that awn has some good options that docky doesnt.
cairo dock have his own session in lightDM and can work with compiz. it use same compiz profil as gnome-classic session. you can in this session load unity 2d panel and have something like unity but istend launcher and dash, you have cairo-dock. pretty good, low resourse usage compare to unity 3d look in the link