As you already know since they are introduced early in Fallout 4, you can get your very own Power Armor, and you can even do so right away if you choose to join the Brotherhood of Steel or help the Minutemen. There are a couple of models that are worth acquiring, and here are some that are worth the effort.
X-02 Enclave Set
There are several ways you can obtain the X-02 Enclave Power Armor. One is by starting the Echoes of the Past quest. You can do so by tuning into the mysterious which will trigger the quest. You will then face Enclave soldiers wearing the armor and you can just loot the parts.
You can also go for the Speak of the Devil quest. You can head to Wattz Consumer Electronics and follow through with the quest. At the end of it, you will find an X-02 Power Armor, which is arguably better since it already comes with a Power Armor frame.
Quantum X-01 Set (Nuka-World DLC)
Probably among the most difficult Power Armor sets to acquire, not only because you'll be facing a lot of enemies along the way, but also because you have to collect 35 Star Cores from locations within Nuka-World.
There aren't any spare Star Cores, so you must acquire every single one. That means exploring every corner of the buildings that have them, which is indicated in the Starport Nuka terminal. No worries, there are guides and playthroughs that can help you find them faster.
Nuka T-51 Set (Nuka-World DLC)
Yet another Power Armor from the Nuka-World add-on, it bears the colors and logo of the company giant you will see throughout the DLC and the base game, Nuka Cola. You won't actually have to do much to get this set.
You will be able to find it in the Bottling Plant in Nuka-World at the World of Refreshment. It's right at the end of the Quantum river. It's in a locked location so you have two options. You can either unlock the terminal (Expert level) or you can acquire the password on a table up on the rooftop.
Atom Cats T-60 Set
Unlike the two previously mentioned models, you won't need any DLCs to acquire this. All you have to do is head over to the Atom Cats Garage south of the map west of Warwick Homestead and purchase the paint job from Rowdy.
You can also purchase the parts and the Power Frame armor directly from her if you don't feel like changing the looks of any of your existing Power Armors. They will always have the painted T-60 set, but you can also purchase other parts with varying models.
Vim! Pop T-51 Set (Far Harbor DLC)
Vim! Pop is another beverage brand within the Fallout universe, and they have their own custom paint Power Armor as well. Unlike Nuka-Cola's, you can actually acquire the paint scheme for the armor and apply it to other T-51 armor.
You can unlock the paint scheme simply by reading the Vim Paint Job Schematics from the Ambassador terminal in the Vim! Pop factory. If you want, you can just take the T-51 Vim! Pop Power Armor that's already in the factory next to the Power Armor station.
