If you are only interested in trading platforms then at the moment uniswap is already tge best, it has the highest volume, many projects are launching on uniswap so it is also an alterbative to the launchpad that trafitional exchanges offer.
It offers all the benefits of a dex alongwith earn8ng opportunities like yield farming.
It has become so popular in a short span of time that top centralized exchanges are now feeling the heat.
There isn't a group of people who examines all the Defi as to which one is the best. Traders prefer to use Uniswap because they can see the opportunity to make money not just by providing liquidity but also doing arbitrage. There are also people suggesting Aave for lending. But I think its too early to say all these when everything there is isn't yet laid for all to test. DIA for instance is like LINK for ORACLE Services so maybe we'll see some shifting in the futrure.