I can share what I know about the Cardano NFT (CNFT) scene that I'm heavily involved in:
The space is still nascent compared to ETH NFTs, but with dramatically lower fees than ETH (typically .17 ADA).
You can find the main secondary marketplace here (admittedly a work in progress): https://cnft.io/.
Others include https://tokhun.io/ and the promising (but currently unreleased) https://exnft.io/
Ideally, you want to get in at the initial drop level, not the secondary market if possible. You can find info on drops here: https://www.wencnft.com/
You can see analytics on projects to discover good ones here https://opencnft.io/ and here https://cnftanalytics.io/
You can also find rarity information on many projects here https://cnft.tools/ and here https://www.tokenref.com/
You will want a good ADA wallet as well. I connect my Ledger to https://ccwallet.io/ but another popular one is https://yoroi-wallet.com/. You can also run the full node official Daedalus wallet if you like https://daedaluswallet.io/.
My experience is mostly with the Cardano NFTs, though I have a small handful of ETH NFTs. I personally lean more towards NFTs that come with additional utility such as in-game advantages for those that will be used in future games, or those that unlock access to additional opportunities. Much to my chagrin though, the NFT projects that tend to moon are the ones that can be used as profile pics since people like to use them as digital flexes of wealth. Very popular Cardano projects that fall into that category are:
1. SpaceBudz https://spacebudz.io/
2. Clay Mates https://www.claymates.org/
3. Yummi Universe: https://yummiuniverse.com/
My personal favorites are:
1. Cardano City: https://cardanocity.io/
2. Cardacity: https://carda.city/#home
3. Hash Guardians: https://hashguardians.io/
4. Cardano Keys: https://cardanokeys.com/
To view CNFTs once you have them, go to the following link and add your receiving address to the end of the URL: https://pool.pm/