Seiko ST-747

I use this to tune my steel-string acoustic guitar. It is very easy to use with both an LCD "analog" meter, and low-correct-high LEDs (red-green-red). Uses a 9-volt battery. It quickly steps through A-A#-B-C-C#-D-D#-E-F-F#-G-G# by pressing the "Note" button. You can also choose any specific frequency from 435 Hz to 446 Hz in whole-number steps. Automatically accepts octave tunings (Set it for "A" and it will read "correct" when it hears 440 Hz or 880 Hz.)

I'm no musician, which is why I needed a tuner. But I can use audio gear. Playing a 440 sine wave from my signal generator, the tuner locked onto the green "correct" LED. At 441, it flickered between the green "correct" and red "high" LEDs.

Pros: Accurate, easy, light weight, small, long battery life.
Cons: Grey-on-black lettering and case are a bit hard to read.