RocketDock by Punk Software is a great Mac OS X dock clone for Windows. It is bouncy when you mouseover, allows you to drag and drop new shortcuts to the bar, and lets you customize all the settings, including the icon height, opacity, and even edge offset. I really like this clone, because it ships with many skins to further integrate your computing experience. It offers a myriad of options which makes it fairly versatile.
Besides being nifty, usable and having a small memory footprint, RocketDock is apparently also is a big hit with wired three-year-olds. Mine just asked to "do the rocket things", meaning he wanted to run the mouse over RocketBar and watch the icons jump up and down. Talk about a selling point.
More screenshots after the jump...
This is the general settings screen. Here you can set many options
The icons settings screen. You can set things like icon image quality, size, zoom, width, and duration.
Next is the position screen, which is helpful for setting the edge offset to bring RocketDock up above your Windows taskbar. This works for any side of your screen, which you can also set here.
And last is the style screen. Here you choose the skin (yes, all those skins pictured here come preloaded, and then some), opacity, and other style options.