What's a good graphical SFTP utility for OS X?
Cyberduck (Free)
A great free FTP client. This is my go-to application. Anytime I need FTP access, I use Cyberduck. It's not quite as lightweight as Fugu, but it adds a lot more functionality than Fugu. I also really like the Growl integration with Cyberduck.

Fugu (Free)
Awesome little FTP client. As I noted above, this is a lightweight FTP client. It is great for simple FTP transfers and browsing. I do like the dual panel navigation.

EDIT: I forgot to add these.
Filezilla (Free)
I haven't actually used Filezilla extensively, but from what I've seen of it, I really like it. I downloaded it and played with it for a bit and I really like the tabbed connections. I also like the ability to jump to a path easily.

RBrowser (Free, $29 Upgrade)
A free FTP/FTP-SSL client. I don't usually use RBrowser because a $29 upgrade is necessary to unlock other protocols (Local, FTP/SSL/TLS, SFTP-SSH). I do like the Site Manager. It's a handy little thing to have.


I searched and came up with some other free FTP clients:
FireFTP (Free) - Firefox extension
The one downside I see is that this is for Firefox. The website doesn't make it clear how it works with Firefox, so I assume it is an extension.
Macfusion (Free)
This one relies on Google's MacFUSE. Since I don't know anything about MacFUSE, I don't know if this is good or bad.
Transmit ($34) By Panic
I have never used Transmit before, but I have used Coda and I definitely would recommend anything from Panic. The only reason I haven't used this because of the $34 price tag.

ForkLift2 ($30)
Never used it, just found it when searching.
Fetch ($24 per user)
An amazing program with a long, long, long mac heritage. It's way up there with Transmit by Panic and Interarchy as a file transfer program loved by long time Mac power users.
Flow ($30)
Never used it, but looks good from the screenshots. I really like the fact that it looks like Finder. I may have to give this one a try.

OneButton FTP (Free)
Just searching around and found yet another one...It looks pretty nice, except it's no longer supported. However, you can still download it.