IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
Faviconer - Faviconer.com, or favicon generator, is online tool for creating favicon.
icon sushi - @icon sushi is icon converter that supports xp icons, vista icons, bmp, png, psd, exe and icl.
ConvertIcon! - Converticon is a simple icon utility.
icoworks - .ico editor for Windows 8 and Windows RT
Ordinatore - Those who want to tidy up their Macs will surely love this application.