Well I store my altcoins on Metamask and Bitcoin on Electrum apps, using those two already made me comfortable when moving my balance to other exchange. Until now I never faced a problem with those two except for a mistake I made myself when I opened a website I didn't check if it real website or phishing in the end I login to Metamask the phishing website and lost all my funds.

You can check for the top Desktop wallet here for reference: https://coinledger.io/tools/best-crypto-wallet