hey 6pack. if you really wanna become someone with "6pack" abs then notihng beats a proper gym with a proper trainer (which is a must, unless you are a mid-pro, or u have friends who can join you). even a 1 hour regime will be enough to keep you fit (until and unless you want to compete) but joining a gym is a commitment in itself, you really need to go to the gym a minimum of 3 times a week.
or else the other best possible alternate is a daily dose of cardio exercises that include jogging / walking / cycling (45 minutes every morning is more than enough) and if you can include some stretching exercises along with it the best. the more healthy your heart remains the longer chances of your survival becomes. along with that include healthy eating habits.
As Rahul said dont fall for such equipments. buying a personal multi-purpose gym can be a bit exciting for the first few days but later you yourself will become lazy to use it.
All this will lead to a healthy body - jo aapki umar lambi karega.