From a historic PoV, which countries were more likely to experience a communist revolution.
Those who's political system geared torwards freedom or those that were oppressive to beginn with?
Pretty much all of Europe has had a substantial communist movement at some point; usually near the beginning of the 20th century. Some have had it more recently; such as the UK in the 1980s and in Greece today.
Socialism became somewhat popular in Britain when the government started privatising inefficient industries such as mining. As the government was no longer breaking windows this made people fear unemployment; commies like Scargill lead protests and used trade unions to cause disruption and bring down the government (ultimately failing).
The October Revolution was triggered by the First World War. It could have stopped at the February revolution if not for the war.