I'm going to start off with that there is no universally best routine. Only what is most appropriate for you given your level of training, physical development, and your goals. Advice in the world of bodybuilding (i.e. hypertrophy work), opinions are so severely divided that it's even hard to compile a list of routines. That's probably due to the fact a number of bodybuilders go to the gym with a rough idea of what they want to accomplish, and the rest kind of falls into place after that.
The best thing I can recommend is hire a coach who has had good results from his clients, and see if you can get 3rd party opinions about his coaching results and style. They will help you figure out exactly what is going to work for you.
However, to that end I do have to outline a couple of things:
- 5x5 routines are a decent compromise for getting stronger and a little bigger. However, they are general programs and you will get general results.
- Most people only see quick results when they are beginners, so doing just about anything will give them results. There are some people who don't see this, but after years of hard work they still get results.
- The more you train, you will need more variation to your training stimulus.
- Even if your emphasis is hypertrophy, you will need to do blocks of emphasizing strength so that you can build more mass later. The reverse is also true.
The bottom line is that to develop a routine that works for you, you'll need to be really smart:
- Log your work, sets/reps/timing/type of work, as well as how you are feeling (fatigue levels), scale and measurements.
- When you get more results with a style of training, keep at it until you start to stall.
- When you stall, change the focus of your training to emphasize a different aspect. I.e. if you have been training for size, start training for strength. This is called periodization.
- Approach any new claims you hear with a healthy skepticism. If the arguments seem sound and don't conflict with anything concrete you already know, you may decide to give it a try. Just make sure it fits your current goals, and feel free to make modifications to make it work best for you.
There is no best. That concept is a marketing ploy in the fitness industry. There's what's best for you give your training maturity and how you respond to exercise, but there is no unequivocal best approach to training for everyone. You might find that what works very well for someone else doesn't really do anything for you. There can be any number of reasons for it ranging from training maturity to personal genetics. Just train, and make minor tweaks as you go along. After a decade or so, you'll have a very good idea of how to train yourself better than anyone else.