Run in Boot Camp if you have the space, but I wouldn't Boot Camp on a 128GB SSD. Also, running Windows in a VM is going to decrease your SSD endurance as double the pace, since you're basically running two full OSes on one system.
You don't want to have to replace an Apple SSD before you get a new PC. They use a proprietary NVMe connector, so the drives are really expensive. I don't think Apple gives Endurance Ratings for thier SSDs, but I'd rather not do that... When SSDs start going bad, they do so more spectacularly than Hard Disk Drives... Also, NVMe drives pull more power than SATA3 SSDs or Hard Drives, and produce a fair amount of heat under load. They will thermally throttle if they get too hot.
There are Windows Gaming Laptops for $1,100 which give better performance than a $2,600 15' rMBP. If you are into gaming, then you need to think about that in the future.
I use virtualbox.
1st I only have 120GB.
2nd if I want delete windows, there's one file only. If you delete it, everything goes with it.
But honestly, if you'll use it for gaming, I don't think this is the best choice, and paralells too.
EDIT: installed Windows with bootcamp and I’m very impressed. It runs better than a PC. And to remove it’s the same, just open bootcamp and click next. Apple always making things simple!
Macs are nothing but PCs with Apple Branding and macOS instead of Windows or Linux.
Given that simple fact, the idea that it runs "better than a PC" is quite an ignorant assertion.
You can literally piece together the same hardware Apple uses for their PCs, except you'd use a Samsung NVMe SSD instead of their proprietary connector, and you'd need a 3rd party display...
Windows won't magically run worse simply because the PC you built doesn't have an Apple Logo on it...
While that sounds cute, here... it's actually a pretty clueless thing to say.