Listary

PRO
It's also a launcher
Once you find the file you need, you can launch it or use custom actions.
PRO
Search as you type everywhere
You can start typing on the desktop or any folders and it'll just search for you.
PRO
Supports other explorers
It supports not only Windows Explorer but also XYplorer, Directory Opus, Total Commander and all the other explorer alternatives.

Locate32

PRO
Remembers searches
Can also export to file
PRO
Backup settings
PRO
Customise search databases
Drives and folders
PRO
Regexp support
PRO
Filter searches
By name, file extensions, location, size, date and more.
CON
Functionality to find text or data in files is in a primitive state

MythicSoft FileLocator Pro

More commonly referred to as Agent Ransack, though that is the Lite edition, FileLocator Pro gives fast search facilities over a number of disparate resources. NB: Agent Ransack (the free edition / FileLocator Lite) does not include the PST search functionality: http://www.mythicsoft.com/filelocatorpro/features FileLocator Network is an additional product which allows you to distribute search processing across multiple nodes; especially useful when searching on devices distributed across a WAN: http://www.mythicsoft.com/filelocatornetwork

PRO
Powerful
Good range of search capabilities.

Everything

Locate files and folders by name instantly.

PRO
Clean and simple user interface
PRO
Quick searching
PRO
Real-time updating
PRO
Small installation file
PRO
Minimal resource usage
PRO
Quick file indexing
PRO
Share files with others easily
CON
Only searches file names, not within files