There are so many options partly because people have different needs/expectations. You need to narrow down the selection by deciding what features you would like. The first is probably resolution; 1080p, 1440p, 4K, ultra-wide, etc. After that, there's the refresh rate; 120Hz is a perfectly good experience for many, but some competitive gamers do benefit from very high refresh rates, like 240Hz and above. It then comes down to how much you are willing to spend and how big you want to go. The ROG monitors pages have a filter which can help you see just the monitors which have particular specs/features that are important to you.