VisualHub produces the best quality results and is drag-and-drop easy to use. One fault with VisualHub is that it doesn’t extract and convert multiple TV episodes (or “titles”) from a single DVD or ISO file; It converts only the last “title” from a multi-episode disk or image file. For multi-title conversion use Handbrake or MacTheRipper.
iSquint produces lower quality results, but is even simpler to use than VisualHub, with less output possibilities and adjustments. For basic conversion of video files to various iPod formats or iPhone, this will work.