Electrum for BTC is the best choice as desktop and even mobile wallet, of course if all the security procedures are followed and the devices where we use this wallet are virus/malware free. If OP is need some multi-currency wallet things are changing, and any free solution probably has some disadvantage. I personally tried the Coinomi desktop wallet, and I have no complaints - but as a longtime user of hardware wallets, I'm used to a higher level of security.
Accordingly, for anyone who is thinking of investing heavily in crypto or being a long-term holder, I advise investing first in some hardware wallet. If someone is investing a few hundred dollars in BTC, then it makes sense that he should invest $50 in the security of his investment.