+1 Lutris - Makes playing Windows games through WINE a breeze.
+1 Brave - A privacy focused Chromium browser (available for all major OSs, even iOS and Android).
+1 stubby - Offers the ability to round robin (you can use an unlimited number of DNS servers as opposed to two to three) DNS over HTTPS for an added layer of privacy. Very nice to have if you have an ISP who snoops on everything and you don't want to shell out for a VPN.
+1 i-MSCP - This one is more for your web hosts/network admins, but it's an excellent FOSS alternative to cPanel and WHMCS. I've ran it for years for my own personal use, and it makes running a web/mail/FTP server stupid simple.
+1 ownCloud - This is another web application, but if you've ever wanted to run your own version of Dropbox or GDrive, this is for you.
+1 Transmission - Possibly my favorite torrent client. It's no frills, a standard for private trackers, and the web daemon is very nice for seedboxes. You can even easily implement the daemon into ownCloud, so you can get whatever you torrent automatically sync'd to your local PC.
+1 Polybar - For the ricers. If you don't run a DE, and just stick with a WM, this is a highly customizable panel. It's like if tint2 and pypanel made a baby.
+1 Evolution - The GNOME email client. It has a similar layout to Thunderbird, but is still maintained as opposed to the latter.
+1 Spotify - Hear me out on this one. Aside from the Android version, the Linux Spotify client can be easily "cracked". You can't get all of the premium features since they're server side, but you can at least block all the ads by patching the client component that handles ad requests. This is much preferable to the Windows and macOS variants, which require running third-party software just to achieve the same effect.
https://github.com/abba23/spotify-adblock-linux
+1 Proton - This is Valve's fork of WINE, which has been revolutionary for gaming on Linux. It can also be incorporated into Lutris for those games that benefit from Proton but you don't own through Steam.