I trained mostly for aesthetics for almost 20 years. This year I decided to start training for overall strength and power. I started with 5x5, experimented with the Hepburn method, reverse pyramids, and 5-3-1, and have progressed to a modified Texas method. If you're big three are sitting under 800lbs (squat, DL, and bench), 5x5 should yield great results for you. Once you approach that 1000lb mark, you'll probably need to work towards mad cow or Texas method.
5x5 helped me add about 50lbs to my squat and deadlift, and a good 30 to my bench. I've been adding between 5-20lbs to each of the big lifts since adopting the Texas method.
Work in some Olympic movements too, and you'll see some impressive results.
There's a ton of good resources for all of this online. Have fun, and good luck bro.