CuteFTP Professional. Nothing out there like it imo. I started off using it around v4, moved to SmartFTP for a while, and then moved back to CuteFTP with v7 Pro last year.

Got it for the bargain price of $30 - don't know if they still do this but, after the trial, they had a survey they asked me to fill in. I said I liked it, I was interested in purchasing it but wouldn't, and then said the reason why was that it was too expensive. 50% off coupon and 10 minutes later it was purchased Goes to show some surveys ARE worth filling in!