I have done various cardio routines, walking, running, HIT, walking on incline, stair master, rowing machine. HIT and running were great for quick results, walking is ok, but your diet still has to be in check and you have to be real consistent, with Running (20mins) and HIT (20mins) i dropped weight quick and my diet was ok at best, i cant stay away from bread..
Stairmaster didnt do fuck all for me, im not dissing it but its not for me.
Rowing machine, i just dont like it.