I Use RKLauncher, and was very surprised to hear that some people use Rocket Dock and even Moby dock still...
Back in the day I used Y'z dock because it was simple, but now RKlauncher has proven to have the simplicity of Y'z dock while also having more customisablility...
but theres other docks ive never used or needed to.... which may be awesome.
so my question now is what dock do you use and why?
EDIT- forgot "AQUA DOCK", if so vote other... and say "Aqua dock" in ur comments.
OS X Dock rulezzzzz 
Object Dock was my very first Mac emulation download so I'm partial to it.
OS X Dock rulezzzzz
Well I guess i forgot that one
the simplest of them all though...
What I like most about it, is that u can drag in folders, and when you hold the mouse button down on those folders, a menu full of its contents comes up
I'm using Yz' right now 'cuz I don't use the minimizing in RKLauncher, and I like the drag-n'-drop feature in Yz'.
And the bounce effect in Yz' is nicer than in RK.
Yz all the way to the end..... I tried RK couple of times (with different builds), but it never went simple and was never able to set in my mind. Besides I found that icons looked better on Yz than RK (anti-aliasing while zooming and so), but then again it could be just me. Overall, I found Yz to be simple, easy to set up than all and less memory eating dock.
I use OD, It animates smoother than others I've tried. I just like it.
On the mac I use the one that ships with the software... it's bloody awful!
object dock all the way... never tried anything else ... it's not buggy.... the animations are smooth.. and iv never had problems using it.. in terms of usability .. its a breeze...
Using Rk, it does everything I need in a dock.
Tried Y'z, I liked it but the pc didn't 
Just started using Rocket, when I say "just started", like 3 days ago.
Big fan of RKLauncher. When my laptop was made up like OS X Tiger, I used it, rather than Object Dock.
OD is fine, but imo, RK Launcher is better.
I'm not using one right now, but last time I used RKLauncher.
ObjectDock was having memory leaks (the animations weren't smooth!). I use the AveDesk tabbed dock sometimes, though...
I have tried using object dock plus and RK launcher, yet Rocket dock seems to be the only dock that works seamlessly with my double monitor setup
object dock is the only other dock with multi monitor capability and was very very sluggish on my computer (not a hardware issue either) and rk launcher had limited features
Rocket dock all the way! and since the new version has compatibility with nearly every skin out there, why doesn't everyone use it?
Started with Y'z & Aqua Dock then moved to Object Dock then RK Launcher. Have been using Rocket Dock for the past few months & will stick with it. It's improved greatly plus I like the UberIcons effect. 
Rk Launcher though i think the development has ended in a way, Raduking has such a exciting life i believe. Still My bote went to RK Launcehr
RKLauncher. Why not?
RKLauncher is just so easy to use...ObjectDock is harder to configure, and the default set is the worst! (Some of) the icons are cool, though.
...and was very surprised to hear that some people use Rocket Dock and even Moby dock still...
I'm confused.. rocketdock is actively being developed upon, it's most recent release was less than a week ago and brought with it animated minimizing (and maximizing) of windows with multimonitor support, why would it be suprising that some folks use it?
I still think RKLauncher's zoom algo's feels the nicest, but I've been using RocketDock for awhile now.
But it's Yz's implementation of the dock's layering behaviour: "Normal/Always on top" etc. which seems to work the nicest with window focus and everyday use. This is my most sadly missed characteristic of Yz.
This application called Dock, actually.
But seriously, I used rklauncher, and I still keep an eye on Rocketdock.
I used RK Launcher for a while, but it started being weird on my pc and it messed up Norton for some reason, so now I am dockless, but i found RK Launcher very simple, and worked very well
I've been following development of both RKLauncher and RocketDock, trying the different builds as they came out, but still I stick with yzDock: it's lighter and the animations "feel" better somehow. Moreover, it has three killer feature that make it my choice:
In the end, I use the dock as a shortcut bar more than a taskbar replacement, so I don't need fancy features and I can use a 4-years-old program. It's a pity Yamaguchi was stopped - now Apple doesn't seem to care that much - all I dream of is an anonymous source code leak, one day 
I totally agree with Dreadnaut... and speaking of that, Thanks Dreadnaut I didn't know about second feature before.
I have been using Mobydock since its early days, and for a very long time, so I had to vote for it.
Now I'm using RKlauncher. One thing I love about it is that it's portable (no installation required)
Yeah, I always prefer using portable programs, but some people have told me that programs requiring an installation tend to be more safe/trustworthy than pertable ones.. This makes no sense to me... but oh well.
I have used Aqua dock and Moby dock and I didn't like either of them, I don't remember details, it was a long time ago, but they both had a bunch of glitches that made me feel like I was using something Microsoft packaged with Windows 2000..
RocketDock. Seems to be the only one that is still actively developed. Rk Launcher is nice, too, but doesn't seem to have moved out of beta. The last build was in August, I think.
For me, RocketDock has the smoothest animations and the popup on mouseover works better.
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