When it comes to overall muscle development, three lifts rise to the top. The flat bench press, squat, and deadlift have been around since weights were made into plates and continue to build impressive physiques til this day. They have the ability to target virtually every muscle group when executed correctly and can increase size as well as strength.
The bench press might be the most well known of all lifts. It targets the chest and pulls the arms into action as well. This movement can be executed with a standard barbell or dumbbells. Remember to resist flaring the elbows to reduce pressure on the shoulder joints and to use a manageable weight. Also, there is no shame in having a spotter, in fact, if you plan on getting the most out of it, I recommend it.
Bros don't let bros skip leg day and if you're going to work legs, some sort of squat must be included. Squats work the entire lower half. You can go with a lesser weight and really rep it out in the rack or up the weight and lower the reps to really build your leg power. Again, a spotter is highly recommended. Also, different variations of the squat can really make a difference in your workout. Front squats, overhead squats, split squats, and dumbbell squats distribute the weight in different ways and activate other stabilizer muscles to really burn out your legs. You will be surprised how much your other lifts increase in weight when your legs increase in strength.
Of the big 3 lifts, my personal favorite is the deadlift. It's a real Cave Man lift. It's loud and heavy and just all around badass! Pick it up and put it down, that's all there is to it. This is a lift where you can really show off your total body strength. The entire posterior chain is worked and you will definitely feel it for a few days. As with all lifts, to minimize injury, you really need to focus on using proper form. Deadlift form is particularly important because the back ties the entire body together. If that goes, you go. But when this movement is performed correctly, you will no doubt have an audience in any gym.