or Domino (light weight, easily configurable version of BT4)
[soapbox]
Biggest difference is that on BT4 you first drag around your bars, try to remember the bar number, then go into the configuration menu to configure the bars. In Domino you do that all on-screen. Drag the bar, right click to configure, middle click to hide, etc. Personally I find it so simpel to use that I've dropped BT4 completely. Domino also supports more customisations (like moving, resizing and even hiding loot-roll popups)
[/soapbox]