I joined my gym just over 2 years ago after giving up smoking and wanting to get in shape. I started doing 1 combat class per week, which i became addicted to after the first class 
and that gradually went up to 4 times a week.
I then added Pump because i was told that i should do some strength work as well as cardio work. I also became addicted to that so decided to try some of the other classes out as well.
I now do combat, pump, jam, spinning / rpm, balance (and boxercise, which i know is not les mills...but hey, its fun). I also do the occasional attack class as well. I have gone from doing 1 class a week to 14 classes per week. I absolutely love combat, jam and rpm.....just cant get enough!!
Go Hard or Go Home!!!!