Casio M5610U with a metal mod I picked up for $99 and I love it! Pick up and go with never a care for durability or accuracy. World time across 5 presets, that you can swap back and forth with your home time at a press of buttons, solar powered, and radio receiving for auto updating of time and date.
What's your cheapest watch in your collection?
My collection of Swatches.
Fun fact : people tend to believe SWATCH stands for "Swiss Watch", which it doesn't. It's "Second Watch", the marketing purpose being to make an affordable watch for people to wear in every days life without wearing to much of their mechanical watch. The main purpose being to save the Swiss mechanical watch industry from the Japan induced quartz crisis.