photoshop cs5 for image editing (it's easier to get around than gimp)
dreamweaver cs5 for html editing (if it actually worked on os x yosemite)
audacity for sound editing (mostly just trimming sounds and recording via line-in)
imovie for video editing (it serves its purpose for light editing, which is what i do)
filezilla for ftp (it's not the best, but it works pretty well)
the unarchiver for decompressing files with extensions that aren't .zip/.tar.gz (such as .rar, .7z, etc)
if you haven't caught on yet i'm using a mac