I am somewhat of a "workout program" snob for several reasons.
1. There are a lot of folks in the gym who have no idea what they are doing or why they are doing it
2. There are a ton of junk personal trainers out there who set their clients up with a typical split body routine (4-5 day). This is a waste of time.
3. Most folks spend way to much time on machines and isolation movements.
Unfortunately now a days people change programs like underwear. And there are so many programs out there that try to sell you some "secret" formula workout routine. It is all ********. I've seen some of the same people in my gym for the past two years, doing the same routine and lifting the same weight. Your body is lazy. Building muscle is the last thing on your body's to do list. You have to stress your body and progressively lift heavier if you are every going to build good muscle mass and strength.
If you truly want to build muscle mass and strength then go with legendary programs like StrongLifts or Mark Rippletoe's Starting Strength (there are many other variations of these that are fine as well). These are classic 5x5 or 3x5 programs. You only do the main compound lifts - barbell squat, bench, barbell row, overhead press, and deadlift. Starting Strength adds in Power Cleans. These programs are built upon progressively lifting heavier. Every time you go in the gym you add 5 more lbs to the lift. These programs work because they are no nonsense, simple programs that have worked for the past 100 years. Classics like Reg Park, Bill Pearl, Arnold, etc all did some form of 5x5 at some point. You don't need some fancy dancy 20 excercise workout 5 days a week. Any new lifter (or anyone that has not done some serious weight lifting in the past) should be doing a full body compound movement routine like 5x5. You have the bonus of "newbie gains" as your body responds very quickly when you stress it with these big compound movements. The beauty of these 5x5 programs like Stronglifts - they are 3 days a week.
As you become a more advanced lifter you move on from these programs as you plateau. This is where you benefit from split body routines or more advanced programs where your at a level that your body really does need more rest in between workouts (hence why you workout certain muscle groups on a certain day). But until you reach that point their is no reason to NOT do these full body compound lifts (and yes all 5 main compound lifts work your entire body if you are doing them with proper form).
I am naturally an ectomorph (skinny, lean, tall, "hardgainer"). I weighed 160 lbs forever, I am 6'1". I tried all sorts of typical split body routines. I saw results, but they weren't spectacular. Did a ton of reading and research and gave Stronglifts a shot. Now I am 195lbs (and no I am not anywhere close to fat or chubby). My strength and lifts have gone up significantly and I have yet to plateau. It is also a lot of fun as you are progressively lifting more weight everytime you are in the gym. You really see results and progression. StrongLifts 5x5 also has an amazing app for your phone that you can track everything on. It is dead simple.
TL;DR - Do a 5x5 program if you want to build muscle mass and strength. StrongLifts or Starting Strength.