DataTips in VS 2005
Jim Gries blogs about the enhanced Datatips in Visual Studio 2005 (damn it's hard to stop saying Visual Studio .NET). Somehow this improvement had escaped my attention previously. All I can say is - wow, wicked cool. Even his screen shot doesn't do the feature justice - this is one of the coolest debugger enhancements I've seen in a very long time. I use QuickWatch a ton, and I can easily see this replacing QuickWatch for 90% of my debugging needs. It definitely gives visualizers a run for their money as the coolest debugging enhancement in VS2005.