I've just recently started into KB's myself. The workouts I have enjoyed so far are.....
Bob Harper's as noted above. I am not a fan of this guy but really really enjoy these two workouts. They are expensive at Target but practically half price through Mary when you add 10% off and buy during one of her sales. Length is around 3/4 hour
I am loving Amy Dixon on Fitnessglo. You can stream for free for 2 weeks (I think) to try it out. Then, it's $12/mth. I kept it - for now.
I really like Providence - that's a goodie. Time Flies with this one. Under 1 hour.
I have Lauren Brooks' newest one. It's expensive but effective. 3 approx. 22 minute segments so can use as add on's.
Angie Miller's is a good one too - straight forward but also effective. under 1 hour
I have a couple of BJ Gaddour workouts (Love this guy) - 30 minutes
Paul Katami's one for beginners is actually really good. I don't do the instructional workout but the other two are great. I also have his KB drills - a few twisty moves that I do not like in this one but it's good. his workouts are around 25 minutes each - or so.
Amy Dixon Raise some Bell - I like this one but I really like Amy Dixon.
Brook Benten is.... well you sure get your sweat on and her dvd's are fairly inexpensive however..... hmmm, how do I say this politely - she does not strike me as the sharpest tool in the shed so many of her comments bother me like "do more cardio for less lardio". That said - her workouts are pretty good.
By the way - if you live in a big city try the library. I got Paul Katami and Angie Miller from my local library. I also got all of Leah Sarago's dvds, lots of yoga, pilates (kristen mcgee), KCM etc... So many finds at the library.
If I think of any others I will edit the post.
I hope this helps a bit.