The CDC recommends 30 minutes of activity a day. Doing this will help to drastically decrease your chances of having any heart related issues.
Now 30 minutes is not a lot at all, and that is why I am going to recommend you get one hour of exercise every single day. To do this all you have to do is discover a passion. Some people like running and other people like biking, either one of these activities is going to drastically improve your life. All you have to do is become active and you will notice your body and life start to change.
Here is a compiled list of calories burned per hour, courtesy of WebMD. 
As you can see some are much more effective for burning calories than others. However, it is good to keep in mind that the amount of effort put into the activity is going to change the amount of caloric burn. 
Find something you enjoy doing and incorporate it into your day. If you start walking at a very slow pace of 3.5 mph for an hour each day with10 days you will have lost an extra pound of fat.