As humans progress in innovation, there will always be sacrifices for convenience. Which is why in the crypto industry, there had been a boom and demand for exchanges for users to conveniently trade their tokens for another, or to fiat.
However, with recent regulations and exchanges being "hacked". there is a growing need to use Decentralized Exchanges(DEXs).

Source: Coindesk
Exchanges have the private keys so when they get hacked(if that is to be true in the first place), your funds on those exchanges are at risk. Though few exchanges will reimburse losses due to a hack, you don't really know until it happens. With new regulations on exchanges, they are now almost just like a bank. Setting withdrawal limits and fees, this is where decentralized exchanges help the crypto industry continue to grow without having it be stifled by over-regulation.
The recent regulations are restricting crypto businesses from providing services to specific regions and is making it more difficult for an average user anywhere to obtain some tokens.
There are a few DEXs that have been up and running for a while now but most that have tried it know that the volume of trades is not there... yet. This is why we have seen some tokens launch with their own "built-in" DEXs and cross-chain compatibility to be able for a crypto holder(or Hodlr) to maintain custody of their private keys and not have the need for an exchange service.
Which Decentralized Exchanges to Use?
While tokens such as Tron or EOS have their own DEXs that you can use and have somewhat of a cross-chain compatibility through pegged tokens or what have you, there are others that really work cross-chain and have many other features.
According to this article from Coinsutra, here is a list of the 10 best DEXs:
To get the best prices across DEXs, you can check out this site here: https://dex.ag/
While some of these exchanges are for specific chains like Ethereum, one that stands out for supporting most of the main top tokens.
Waves DEX(Changing to Waves.Exchange)

Being that Waves is its own token and blockchain, it also works with a centralized matching service. This allows trading pairs of BTC, ETH, DASH, and others possible on the DEX. We do want to be fully decentralized but having it co-exist with a decentralized platform, allows a smoother transition for the volume to move towards more fully decentralized exchanges.
They have a pretty good trading volume and with having trading pairs like BTC/ETH and a simple UI, this allows for a more convenient way to obtain tokens while having the private keys.
Note: Waves DEX is moving their service to Waves.Exchange. You'll receive a notice if you already have tokens to migrate your accounts to the new exchange and is strongly recommended to do so before December 2, 2019.
Edit: The move has been made.

For more information on other DEXs to try, you can check out the Coinsutra article.
If You Don’t Own Your Keys, You Don’t Own Your Crypto
You might have heard this saying and something newcomers to the space need to understand. They need to be treated like actual keys and be secured so that you or the person you want only have access to the funds. While you may trust the security of an exchange service, they are a bigger target for hackers as larger funds are all in one place.
Remember to secure your keys and do your due diligence and do your research.