By far the best simple ftp client out there. I tried Flow as part f the macheist bundle, but despite the good reviews, I didn't find it as intuitive as Cyberduck.
It is freeware, but I will definately be donating sometime soon!

Large file uploads seem to be a big problem. The resume function acts like it is working, but corrupts the file.

great app. I love it. One thing that should be better looked into is the connection flow. Its not clear where you create a favorite link etc. This makes me go to the history and use it instead, which is not very nice. I specially love the feature where you can open a remote file for editing in textmate and have it upload automatically whenever you save it.

I use Cyberduck for my SFTP connections and have never had a problem. It's easy to use, works well, and is totally free :D

On the site U can find a Beta for snow leopard and that one works.

Should add that remote QuickLook is a very cool feature - Cyberduck has become my FTP/SFTP client of choice for web site maintenance, & I'll probably use it for incremental backups.

Works very well but has a not so slow memory leak - from 60MB real memory to 120MB used in about half an hour while uploading to S3. I left a large (4GB or so) upload going overnight and woke up this morning to find my computer frozen -- can't prove it but am almost certain this was due to Cyberduck using up all available memory, since the comp had never frozen before.

Does not work on Snow Leopard due to unavailable Cocoa Java bindings.

I've used CD for a year with nary a crash or hang. (OS 10.4.11 & 10.5.6, macpro & MBP, all intel. UI isn't so hot, but free and in active development is fantastic.

Very simple and, for me until now, efficient. A little time to up/download, but I'm not in a hurry. I'm not a full time user of it, so, it is a good app for the ones that don't up/download tons of files. For a daily use with lots of files, I don't know. I also use Filezilla on a PC and is a great one, but somehow it doesn't work with my Mac MBP 10.4.