Irfanview does that and the interface isn't bad. If you want to convert a whole folder you can do that very easily. If you want to select just some of the photos from a folder to convert Irfanview is the easiest way I know of. It is free: www.irfanview.com
Why are you converting large numbers of files from JPG to TIFF?
Why are you converting large numbers of files from JPG to TIFF?