Still look for a good diff GUI. Currently, I have WinDiff, WinMerge, and ExamDiff Pro.
Generally, WinDiff can meet my requirement when comparing two files, but not directories. I can't believe why MS can't get this simple thing right. All files' name are lowercase listed when two directories are compared. When copying the different files, all files are lowercase.
I wish WinMerge shows line number in the gutter. The default font should be fixed size.
ExmaDiff Pro looks like is powerful, but not free.