China, twice in 2007 for work
Not me, but a family friend (Indian national) lived in Hungary for a year in the mid 1960s, as an engineering student, and became fluent in Hungarian. People were reasonably happy and comfortable, from what he could tell.
East Germany in 1965. I was also in West Berlin and wanted to see East Berlin through Checkpoint Charlie, which I did. The Wall was quite new then.
i have also visited Estonia and Russia since the fall of communism, and I think i was once in Berkeley.
Those damned Atlanta Commies!
Heh, I went through Checkpoint Charlie myself. In East Berlin, someone I’m sure was a Stasi agent made a blatant attempt to entrap me by getting me to exchange money with him. I didn’t take the bait.
China, 2005. We went on a local tour bus to the Great Wall and on the way back, Beijing Public Security stopped the bus, did a walkthrough, and then dragged the driver off and arrested him for no immediately discernible reason. The guide wound up driving the rest of the way back. None of the Chinese people on the bus even poked their heads out of their newspapers, while the handful of Americans were all quietly but frantically fumbling for passports.
Communist at the time:
Cuba
Yugoslavia (in a part in current Croatia).
I’ve been to a number of former communist states in Eastern Europe, but I’m guessing those don’t count.
Just the USSR in 1987.
Somehow I don’t think being in Hong Kong in the 80s counts. So I guess zero.
Only Vietnam, and Hong Kong after it was returned.
I went to the border of Hong Kong and China in the early 80s as well as the DMZ.
China, twice for work. About 6 formely-Communist countries.
Just Canada.
I’ve been in Hong Kong several times, both before and after the handover, and Macau but didn’t really include them.
Any treatment of this topic will be an asterisk playground. Using a Jesse Helms definition, it would be any country except the USA and countries ruled by US puppet. If it counts any country that imported Lada Russian cars or Krakus Polish strawberry jam, Canada would be on the list.
my list for the obvious coldwar bloc would include USSR, Poland, DDR, Czechoslovakia, Hungary, Romania, Bulgaria, Yugoslavia, and the SSRs of Latvia, Lithuania and Belarus. By extension, the present day CIS republics are essentialy as socialist as they ever were, including Kazakhstan, Kyrgyzstan, Georgua, Armenia, Azerbaijan, Moldova, Ukraine. And solidly in the Soviet camp todahy, Transdniestria. Also China, Laos, Vietnam, Myanmar.
Most African countries drifted in and out of the socialist realm in the 70s, and I can’t remember exactly which ones, but I might include Algeria, Sudan, Tanzania, Mozambique, Madagascar, Benin, Zaire, Mali, Malawi. It is usually not appaent to a traveler when you’re in a communist of socialist country.
Countries visited recently with strongly leftist associations ae Guyana, Somalia, Sri Lanka, Ethiopia. At this moment, socialism is constitutionally official in India, Egypt, Portugal.
Missed it by that much!
I was in East Germany 3 days after Einheit. But nothing had changed, so I think I got a good feel for it.
USSR in 1986
Hungary in 1987
Cuba in 2012
Vietnam in 2014
Hong Kong
And inside of a week, we’ll be in Vietnam too! (For one month!)
(Sounds like it’s time for the first ever, Vietnam Dopefest! HaHaHa!)
None while they were; only the Czech Republic after. The Museum of Communism was one of the unexpected highlights of the visit.
Hungary and Romania in 1972. Interesting times.
I’ve been back to Budapest more recently (and to Prague as well) but they’re not Communist in any meaningful sense anymore.
Made three trips to Russia back in 2009 to adopt the Firebug and bring him home. 
That’s the only one I’ve been to.
China (well, I was in Hong Kong), Cuba, Poland (which wasn’t communist when I visited it) and Russia (which isn’t communist anymore, but was when I last visited it). I did a cruise once that sailed by Nicaragua but never visited.