I have a small workshop, (lab is a bit too grand) in which I have a workbench and keep my test gear.
On the shelf are:
Levell TM3A Millivoltmeter (-100-+50 dBu range)
Levell TG150DM Audio Oscillator 1.5Hz-150kHz sine/square, distortion typically <0.05%
Ferrograph RTS2A combined test set. Consists of low distortion sine wave oscillator (distortion @1kHz < 0.015%), Millivoltmeter, Distortion Factor meter (at 1kHz only), Wow and Flutter and speed drift meter.
Leader DM170 Distortion meter. Measures down to 0.05% distortion (0.3% FSD) at any frequency between 200-20kHz
(I currently lack an instrument that measures THD at below 200Hz, but I increasingly use my PC for measurements, so if I need to measure bass distortion, I do it that way.)
Levell Digital Frequency Meter, 5Hz-100MHz
On bench, Coutant LQT100 0-30v 1 amp dual bench power supply
Hitachi V-422 dual trace 40MHz oscilloscope.
I also have a Radio Shack Sound Level meter, a portable digital bit-stream analyser and a small Variac mains transformer.