The best replacement for docky is cairo.

The best alternatives to docky are rated as following:
★★★★★  cairo
★★★★  awn
★★★★  plank
★★★  dockbarx
★★★  cairo dock
★★  glx-dock
★★  gnome do
★★  wbar
★★  avant
★  tint2

Your alternative for docky is not listed? Suggest!
Speaking about docky, one probably shouldn't forget about stacks.

Other search terms related to docky and their ratings are:
★★★★★ stacks
★★★ gnome do
★ xfce
gnome 3
You have in mind a companion for docky and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of docky in all years. Click on graph for more.
docky
cairo
awn