Dylan's debugging resources
LLDB - a gdb clone built for the LLVM stack. Has some bells and whistles that gdb doesn't.
Radare - a symbolic execution enviornment for reverse engineering-- and in my opinion is hands down the best out of the three. It can generate ascii flow charts of the disassembly, step through and show register values, auto map strings, output graphviz charts of functions, and so much more.
- GEDE A front end for gdb. I found this from the gdb wiki. Most of the GUIs there are unmaintained or deprecated.
- Voltron A tmux gui for LLDB and GDB. (REALLY similar to the emacs setup Jim has) This took some time to get to work for gdb and ultimately wasn't worth it. The gdb gui is glitchy and doesn't update the register values until you stepi a second time. However, for LLDB it was fantastic and real-time.
- Bokken A GUI for radare, as if radare wasn't OP enough.