I got that Your Shape - Fitness Evolved and i have to admit i wasn't impressed. It keeps telling me I am not doing it right when I am sure I am lol. I am sure it's the sensor , doesn't like fatties or something!!
Dance Central is pretty awesome though although not a full on hard workout, more a bit of active fun. All the sports ones are pretty hardcore, seen my son and hubby work up a sweat with those
havent got an xbox so i cant say which is good but one thing is to get different games for it. rather than just doing one contiuously and your body getting bored and used to it alternate it with another one. l
maybe a hard one and a fun one? like sport one and zumba maybe? a workout has to be fun to stick to it