I've been working out at home for about 6yrs now. My favorite instructor is Cathe Friedrich...she will most certainly kick your butt. I love all her workouts, she has a great,refreshing personality that doesn't get old for me.
Jillian Michaels is another one that comes to mind(although she can be scary at times,LOL). I have 30 day Shred, Yoga meltdown, other by her and some of The Biggest Loser workouts with Bob too. There good too!
Here is a link to one of my favorite sites that has reviews, video clips and you can also pinpoint what kind of workouts your looking for and they will give you suggestions.
collage video
good luck