What kind of style does your husband like? Does he like athletic moves, or does he prefer dancier choreography? Is he looking for step? Muscle building? Floor aerobics?
Remind him that he can make any tape more intense by either increasing the weights, adding extra jumps, jumping higher, running faster, making his arm movements bigger, or increasing the height of his step. With that said, there are several really good male instructors he may want to try, although I don't think anyone (male or female) is as intense as Cathe.
I suggest he take a look at:
-- Greg Twombly - CIA video king
-- Andre Houle - his choreography is kind of dancy
-- GForce (Rob Glick, Darrin Grove and Patrick Goudeau)- fun guys, some of them have individual tapes on CIA
-- Gilad - much more athletic than dancy
-- Jay Blahnik - also advanced choeography
-- Billy Blanks - in your face kickbox aerobics
-- Rodney Yee - Yoga, I've never done him, so I don't know his style, but he seems to be very popular.
Written reviews of these instructors and videos can be found at ciavideo.com, videofitness.com and at collagevideo.com. Also, on Collage, he can preview video streams of these instructors. Also, CIA will soon be adding streaming video previews to their website too. This should give him and idea which of these guys he would like working out with.
Good Luck!
Lisa