Muon.

Does SSH, SFTP and other stuff.

I would say, like many others, Remmina.

Putty also has a Linux version, so you can use that as well. Its session management is a bit clunky, but it works and it offers some fairly good functionalities.

But ssh is first and foremost a command line tool. As others have said, invest some time to learn its commands and configuration files.

I use Apache Guacamole, which works great for just about any kind of remote access and has a dead simple to use Docker Container.

It supports folders, copy/paste, uploading/downloading files, multiple open connections at once, and alternative mouse modes for touch screens. Best of all, it's completely free and open source.

SecureCRT. Expensive but my work paid for it.

Termius?

Remmina proves a reliable solution for remote desktop access when a graphical interface is required. However, for more streamlined operations, terminal-based SSH access ssh username@remote_host remains the preferred method. Establishing passwordless authentication is, naturally, a matter of convenience. The command ssh-copy-id username@remote_host facilitates this process. It’s a rather elegant solution, isn't it? A testament to the power of minimalism.

If youre on windows, mremoteng is very comprehensive: https://mremoteng.org/

Rustdesk? Guacamole?

~~Mobaxterm~~?

Stupid windows only.