The first thing that you'll want to look into is a cage and barbell. Of all the pieces of equipment you could buy, this would be the best option. The reason being it allows you to perform so many heavy compound exercises that you'd never do without it.For instance, squats, seated or standing barbell press, and bench press. While you can always use dumbbells, you can't get a heavy enough weight up in most cases to fully max out your muscles if strength is your goal.A cage lets you do so and keeps you safe while you do it.
Adjustable dumbbells are next up on the list of pieces of equipment to look into. The great thing here is that they allow you to do so many different exercises in the same workout without needing any more than one piece of equipment.While any set of dumbbells is good, the problem you'll run into is that you can certainly do more weight doing a shoulder press than you can a bicep curl. Therefore, using the same dumbbell doesn't really make sense.Your shoulders would never be challenged as you'd need to go with the lighter weight of what you can do for the bicep curl.Adjustable dumbbells are more pricy to buy at first, but it's an investment that will serve you well for years to come in your home gym because you won't outgrow them - and it's still a lot cheaper than buying multiple sets of dumbbells as well.
Finally, the third piece of equipment to consider is a resistance band. A set of resistance bands is cost-effective and hardly takes up any space at all, so is super easy to use as part of a home gym.You can perform almost all the same exercises you would with dumbbells with resistance bands so think of it as a good alternative for those who can't have dumbbells.Or, you can get both and interchange between the two when you want a break from the other.If you can get these three pieces of equipment in line in your home gym, you'll see a dramatic improvement in the number of exercises you can do and therefore, the results you see.