AC Browser Plus Free - Little known file manager - very powerful
Nomad.NET - Another powerful and little known file manager - super powerful search - requires .NET 2.0 or later
2xExplorer - Unlimited scrap panes - mirror browsing - lightweight and fast
UnReal Commander - Similar to Total Commander
XYplorer Free - Not dual pane, tabbed, drag & drop copied text automated text file creation
A43 - lightweight, create nested folders, build in text editor
Agent Ransack - File search including content