Unfortunately I've only been to Belgium, Germany, Luxembourg (really close, so not really travel), France, Italy, Turkey, England, Ireland, Scotland, Switzerland (drove through it on my way to Italy :P) and Austria. I'm going to Spain twice this summer though. Oh, and I live in the Netherlands
I was born in Poland but I live in UK.
If being all the way down to Poland and crossing a bridge across the river to Slovakia counts as 'being' in the other country then I could say Slovakia.
It was cool because we went on top of the mountains and there is this river, and if you cross the bridge you in Slovakia.
I felt happy, as we were in the Bar, I was drinking coca cola in Slovakia, and I been there for 20 minutes.
So, Poland, UK, Spain, Slovakia (For like 20 minutes)
You just wasted 5 seconds of your life reading this message, you will now think about something you could have done for these 5 seconds instead of reading this useless message that now made you waste 10 seconds of your life.