Thinking back, I've been to quite a few, but most of them were when I was much younger, to the extent that I barely remember them save for from family video clips. Much less mobile now.
Blighty (lived and studied here for most of me life)
South Korea (lived here for 4 years)
Singapore (family lives here, I still go back occasionally)
New Zealand
Australia
Hong Kong, SAR
Vietnam (when I was very young)
Spain (Barcelona, again when I was really young)
Malaysia (did an internship here last year)
Indonesia
France (Paris, Nice (which wasn't), numerous skiing resorts)
Switzerland (relatively recently, actually)
Los Estados Unidos (Cali. Weirdly, I actually thought I'd never set foot in this country, but it turns out I had, when I was really little)
Canada
oh, and Iceland too, for 4 days of an ill-fated school trip