Answer:
Squats, lunges, running, bike-riding, walking up stairs (two at a time is best). Also exercises at the gym like gym squats, leg extensions, leg press and leg curls.
squats and sprint training.
squats are amazing for the entire lower body, and running will give your legs definition and more power.
Horseback riders have amazing thighs. Try taking a lesson at a nearby stable to see if you like it.
bowflex has alot of stuff for that
squats and deadlifts for lower back, you dont want to train one musle group you wanna do the whole body