If you were to get to your goal weight and you're enjoying 30 Day Shred, you could keep doing it and up your calorie intake (slowly) so you don't lose any further weight. If you want to try a different workout for variety, the possibilities are endless! Some great resources for home workouts are collagevideo.com and videofitness.com.
I'm personally doing an 8-week JNL Fusion rotation which I'm loving! It is about 30 minutes per day and incorporates 30 secs. strength/30 secs. cardio. It's somewhat similar to Jillians stuff...just a different trainer.