With the possible exception of crappy do-nothing text editors, the single most-crowded category for Mac utilities might be file transfer apps. There are a bunch, from old Mac stalwarts (like Fetch, Interarchy, and Transmit) to old NeXT stalwarts (like RBrowser) to brand new apps (like Captain FTP and Fugu).
The app I find myself using most of the time, however, is the relatively unheralded MacSFTP. What I like:
As the name implies, full support for the SFTP protocol. I’m not so security-obsessed that I refuse to use plain old FTP, but since my web host supports SFTP, why not?
A clear, simple interface. You can set a preference as to whether double-clicking a directory opens a new window (I prefer not; as a long-time Fetch user, I like to keep one window per server connection).
Also, MacSFTP only displays remote files. I like this. Many recent file transfer apps display both local and remote files in the same window. I don’t think there’s anything wrong with that; I just prefer using the Finder. A local file list in a file transfer app just gets in my way. (In Transmit, the local file listing is a preference that can be turned off; in others, like Fugu, it can’t be turned off.)
Terrific support for the Edit in BBEdit protocol, including a nifty preference setting that lets you open files for editing in BBEdit by double-clicking them in MacSFTP (as opposed to downloading them when you double-click).
A simple, easy-to-use bookmarks window.
Stores passwords in the Mac OS Keychain.
Runs well on both Mac OS 9 and Mac OS X.
Decent AppleScript support.
It’s not perfect. For one thing, I wish there were a preference to adjust the row height for file listings; the default is too big for my tastes. I also wish the Set Permissions window showed the numeric value for the current settings (e.g. “755”, “644”) because that’s how my feeble mind recognizes Unix-style permissions.
But these gripes are minor. MacSFTP is my favorite kind of utility — it does one thing and does it well. Well worth the US$25 price.