SoftPerfect Network Scanner
I’ve long been a fan of Foundstone’s Superscanner for network scanning. However SoftPerfect’s Network Scanner has some very nice features that has made it a staple of my toolkit.
Namely it offers Netbios scanning, folder/printer enumeration, it doesn’t require install, and it has a great interface. You can find links to this and numerous other utilities on my tools page. Look under Network Tools