I use gdb myself.

I don't know exactly what you're after. From the above, I see:

"easy to use"

" the mouse is faster, not slower"

You don't specify a language, so I'm assuming you're looking for something low-level.

You don't specify an editor, so I'm assuming that you want something stand-alone, not integrated with an editor.

There are a number of packages that use gdb internally, but put some kind of visualization on it. I've used emacs's before, though I'm not particularly married to it

mainly found it interesting as a way to rapidly move up and down frames in a stack

but I'm assuming that if you want something quick to learn, you're not looking for emacs either.

Maybe seer? That'd be a stand-alone frontend on gdb with a GUI. Haven't used it myself.

EDIT: WRT gdb, the major alternative that I can think of to gdb is dbx, and that's also a CLI tool and looks dead these days. gdb is pretty dominant, so if you want something mouse-oriented, you're probably going to have some form of frontend on gdb.

There are other important debugging tools out there, stuff like valgrind, but in terms of a tool to halt and step through a program, view variables, etc, you're most-likely looking at gdb, one way or another, unless you're working in some sort of high-level language that has its own debugger. If you want a GUI interface, it's probably going to be some sort of frontend to gdb.

EDIT2: Huh. Apparently llvm has its own debugger, lldb. Haven't used it, and it's probably not what you want anyway, since it's also a CLI-based debugger. I am also sure that it has far fewer users than gdb. But just for completeness....guess you already looked at that, mentioned it in your comment.