I'm playing with open source simulators again. Verilator and GTKWave still seem to be the masters of the space. I used to use IcarusVerilog for simulating, but Verilator is much faster.
Analog values on a bus are always good visuals for debugging things. I learned to use this mode when trying to visually qualify k characters on a serial link.
This screenshot is the output of an LFSR block with a 16bit polynomial resulting in a 64k value space.