Plaubel Makina 670 and a light tripod is my favorite travelling gear.
I have done a few trips with other cameras, more than one camera, a Leica M8 with three lenses, but in the end I prefer just taking the Makina now for it's superb image quality and small size (considering it's an MF camera).
I also want to enjoy my travels, and pay more attention to what I actually want to photograph, than wondering what lens to use, what settings, reviewing the digital shots etc. A simple camera allows me to keep gear-related attention to the minimum.
When it comes to GAS however, I do have it often after a trip. But it's more about what film could have been a better choice, what clothes would work out better for hiking and things like that.