Cyberduck has worked well for me and I upload a lot, move things around the website, rename. I gave up on CuteFTP for Mac (paid) since it messed up and uploaded most but not all of my photos as text.
I've been a happy RBrowser user since 1999. Feels like you're using the Finder rather than... well, something else. If the Finder's interface is good enough for dealing with files on my computers, then the same type of interface should work when I'm dealing with files on servers.
I am a transmit guy, definitely worth the $30. Being able to edit live with textmate, maintain favorites, and browse my server in Column mode is worth every penny. Did I mention it works really great too?
Everyone always seems to neglect the Fugu. Its also free like cyberduck but for some reason I like Fugu alot better. Course both are free so no reason not to try out both and choose whatever is more comfortable for you.
Apparently there is a way to make it work with FTP though...
"If you must use traditional FTP, use Fugu's SSH tunnel capabilities to create a secure connection to the server. "
But like I said, I don't know much about this stuff.
Another free one is OneButton FTP, which specializes in file queueing. I haven't seen much in the way of updates lately, though. I hope it hasn't been abandoned.
Cyberduck for uploading, anything else and it just stops working for me.
Transmit 3.5.1 is VERY good but I'm limited to the demo. the ultimate I think.