Just been diving into the NFT space and realized there's a ton of confusion about which platforms actually matter. Let me break down what I've learned about the biggest NFT marketplaces out there.

OpenSea is basically the heavyweight champion here. Started back in 2017, it's got over 600k users and hosts more than 80 million NFTs. The interface is pretty straightforward—you can browse trending collections, create your own NFTs, and the fees are reasonable (2.5% for sellers). They've even partnered with Adobe for Photoshop integration, which is actually pretty cool for creators.

If you want something more curated and secure, Foundation is worth checking out. They verify creators through Twitter and Instagram, which filters out a lot of noise. The platform has around 956k users and creators get 85% when they first sell, plus 10% royalties on secondary sales. But here's the thing—you need an invite to create, so it's more exclusive.

For gaming NFTs specifically, Axie Infinity is the go-to. It's play-to-earn focused, meaning you can actually earn while playing. The platform charges 4.25% from sellers and has sold over 2.3 million NFTs. You'll need the Ronin wallet though.

Rarible is another solid option that's been gaining traction. Multi-chain support (ETH, Flow, Tezos), reasonable 2.5% fees for both buyers and sellers, and they accept traditional payment methods like credit cards and PayPal. Already has around 1.6 million users with $274M in trading volume.

Then there's Nifty Gateway, owned by Gemini. No buyer or seller fees, which is pretty rare. Secured wallet storage and you can connect MetaMask if you already own NFTs elsewhere. The main limitation is they only support USD and ETH.

SuperRare is for serious art collectors. Creators get 85% on first sale and 3% on secondary trades. But it's ETH-only, charges higher fees (3% buyer, 15% seller), and only supports artwork NFTs. Not beginner-friendly.

Mintable stands out for beginners because it pioneered gasless minting. You can create NFTs without paying gas fees upfront—they only charge when it sells. Supports credit cards, PayPal, and crypto. Transaction fees are 5% for gasless items, which is reasonable.

ATOMICHUB operates on WAX blockchain and has crossed 9 million transactions. Only charges 2% fees, which is among the lowest. But the interface is complex and it doesn't accept credit cards.

For trading card enthusiasts, MythMarket focuses exclusively on cards like GPK and Heroes on WAX blockchain. Limited scope but loyal user base.

Looking at the landscape, the biggest NFT marketplaces each serve different needs. OpenSea dominates for general NFT trading, Foundation caters to verified creators, Rarible offers multi-chain flexibility, and Axie owns the gaming space. The key is figuring out what you're actually trying to do—collect art, play games, or just explore the space. Each platform has its trade-offs between fees, user experience, and what assets they support. The NFT market's evolved a lot since these platforms launched, so do your own research before jumping in.