In my opinion, USDT is the most stable coin that I use so far for any transaction in most exchanges, moreover if the USDT is mostly used in pairs in the exchanges.
Moreover, this is available in most Exchanges with many pairs. However, it will depend on your DYOR. But there are also some issues that USDT is not recommended for holding especially because of certain problems and issues so far. However, so far, I don't meet the issues.
If you want to look more at this choice, BUSD and DAI may be also a good choice, but it may have fewer pairs in some exchanges.
BUSD might be the right choice because so far I personally have also chosen BUSD as a stable coin to store funds when the market is experiencing a crash like what is happening now
Maybe BUSD is a good choice, but it is limited only in some exchanges, especially only on Binance and also its partner's exchanges. So, the uses may not be as universal as USDT