If you insist on doing cardio and lifting in the same workout, make sure you are doing cardio AFTER lifting or you severly blunt the release of growth hormone and testosterone by doing cardio first...
I prefer doing a form of "hybrid" cardio in the form of EDT blocks(Escalated Density Training), which is both a resistence workout and cardio workout at the same time. You pick 2 exercises and choose a weight you can comfortably complete 12 reps at. For instance, Weighted Dips and 1 Arm DB Rows. You either set a timer for 20 minutes or start on one of the "5" minute markers on the clock. Then you alternate exercises with no rest in between doing as many sets of 5 reps as you can. 5 reps of weighted dips/5 reps of 1 Arm DB Rows...keep alternating and doing as many sets of 5 as you can. After a while you will no longer be able to do sets of 5, you will be doing sets of 4,3,2,and 1...Keep track of how many of each you do, and then tally up the reps and total weight. That is your "score". The next time you do these, you are to use the same weights and try and beat the "score". Once you are able to do between 10-20% more reps than the first time you did it, you can increase the weight 5%. The first few times doing this, you will feel like your heart is getting ready to beat out of your chest and you are sucking air like crazy. Your conditioning improves pretty quick tho, and by the 3rd or 4th time, you aren't breathing as heavy and are doing a lot more reps...
Not only does this shred fat much quicker than cardio does, it also will build muscle since you are activating both the aerobic(cardio) and anaerobic(resistence training) pathways simulatneously. It helps to build Type IIc muscle fibers, which have the benefits of both type IIa and IIb fibers (strength AND endurance)...
Try this for a month and see how you like it...I utilize 20 minute timed EDT Blocks 3 times a week after doing compound lifts and here are what I do:
Weighted Dips/1 Arm DB Rows
DB Squat-Push-Presses/DB Swings
Weighted Chins/Decline Pushups(pushups with feet on bench--makes harder)
I also do High Rep Deadlifts(5 sets of 12) within 15-20 minutes, which is basically an EDT block by itself since they are brutal....