Can anyone recommend a good .rar extracter for free?

[AMNVanNess]

I like fy zip its free and does all compression files

[C0080900]

WinRAR, it can scan archives for viruses before you open them.

Also, keep in mind, you have to add your virus scanner to WinRAR in order for WinRAR to scan for viruses.

[Slacker Magician]

If you want to fiddle with compression settings or use a compressor like PAQ (with a GUI), PeaZip is good.
7Zip is good.
You can also run certain versions of the trial WinRAR without limits.