i think uniswap, polkadot and xsigma are the most promising defi projects, regarding to my own research
While Uniswap standout among the defi project there are more of them that actually better and its orice continue to moon up. Synthetix use to be just less than $1 but you can only have few of it with $1000 today. Every Defi project that somehow people think are just driven by hype just took off.
Aave is definitely the kind of project that you would want to try out.