EasyFind

Unlike Spotlight, EasyFind finds files and folders by name or content using advanced Boolean operators similar to DEVONthink and DEVONagent, wildcards, and phrases. It does not require indexing, is fast, and uses very little memory. Of course EasyFind doesn't just give you the files, it also shows previews and gives you many other options to work with them. And it's free. Life can be so good.

Version 4.9.3:

• NEW: Edit > Deselect All is now an alternate menu item of Edit > Select All and available after pressing the ⇧Shift modifier key (or the shortcut ⌘⇧A).
• Improved: Displayed file size includes now size of resource fork, too.
• Improved: Support for files with no or invalid creation or modification dates.
• Improved: Quick Look panel is faster
  More...
  

Requirements

OS X 10.6.8 or later