Comparing Files: I Use WinMerge

[Thorin]

So I use WinMerge when I compare sets of files to each other.  It's free, it's open-source, and I've found it works remarkably well.

http://winmerge.org/

What do you guys use?  Or do you not find the need to compare files?

[Lazybones]

I use WinMerg as well, but I find that even after tweaking the default settings (IE finding groups of text that have changed order) it still isn't as good as some commercial apps.

[Mr. Analog]

I use WinMerge and to comparison tool in Subversion (thru TortoiseSVN).