I would think that these countries, with their close proximity to Russia and their former membership of the Soviet Union, would remain friendly with Russia. Why haven't they? Also, I apologize if this partially violates the 20 year rule, I hope there can still be some good discussion.
The Baltic States do not consider themselves to be successors to their respective Soviet Republics. They do not accept that they were ever legally in the USSR. This view is also held by the United States and the European Union. In 1991, all three countries restored the Republics that existed prior to the Soviet occupation in 1940.
Here is the "White Book" , documenting the losses suffered by the Estonian nation in the period of 1940-1991 while under foreign occupation: http://www.riigikogu.ee/public/Riigikogu/TheWhiteBook.pdf It should offer a clue as to why there is deep resentment towards Russia in the Baltic States.
It is largely a reaction against Russian domination, on nationalist lines. The fact is that for many countries to the east in Europe, organisations like NATO and the EU represent a power base that fundamentally isn't Russia.
I think the older poster referenced the Holodomor, and while that isn't necessarily correct on a physical level, it is correct on an emotional level, insofar that all these countries have histories under the control of the Warsaw Pact or the USSR or under Imperial Russia. Rightly or wrongly, the Holodomor is a reason to dislike Russia in Ukraine.
Fundamentally the aim of all states is to maximise power (economically especially) and to maximise its own sovereignty in tandem with this.
This, however is largely a conceptual answer and so I understand if sourcing and a greater historical context is needed.