From my experience, if your workout routine is not fun, exciting, and challenging, than it's not worth it.
A steady state cardio program, or a weight training program that has you resting for long periods between each set may or may not be effective - but this is not the point.
An intense workout that has you literally puking towards the end of the workout may actually be just as effective, or even more effective than traditional, non-intense workouts.
However, intense workouts are more fun, challenging, and exciting - which means that you'll stick to the workouts longer.
A recent non-scientific, informal study conducted by world-class trainer John Berardi compared the amount of weight loss between high intensity interval cardio and low intensity steady state cardio.
He found that there was no significant difference between the results.
However, because this study was not paid for and conducted only through surveys, John Berardi found that that the cardio group had an 80% drop out rate, while the interval group had a 55% drop out rate.
This means that you are 25% more likely to stick to an 8-week interval training program than you are to stick to an 8-week program that has you running on a treadmill for 45 minutes per day.
And I believe that if those intervals were bodyweight intervals instead of cardio intervals, you'll have even more fun while working out.
In conclusion, the key to really achieving all your goals is to stick to your program.
You are more likely to stick to a program if the program is fun.
It needs to motivate you enough so that you actually perform the workout the way it is written.