Interarchy is very good! It displays directories just like folders in the finder. Great for dragging and dropping items as well.
I went on a mission to find the best free ftp client when my interarchy trial period ran out. After a few months using every other program I could, I just ended up purchasing Interarchy.
transmit. i used fetch for years only to quickly lose interest after using transmit once. i have a registered copy, best little piece of software that i own.
panic is just an overall great company, great customer service.
I've been using what was supposed to be a demo of Fetch for over a year now. It asks me for money but I just wait 30 seconds and it works. Weird, but I like it. I just read a very useful tutorial on FTPing with the terminal in OS X. Works well, lots of detail though.