sanyer

Kharkiv seems to be by far the most probable target due to its proximity to Dombas. The others seem very unlikely to happen this year. I don't have good inside view on this yet, but I'll try to form one in the coming weeks. For now, I'm somewhat following the crowd forecast.

Moldova seems to be the most probable target of a Russian invasion. Factors that make this more likely:

• Transnistria is very much controlled by Russia, and has 1,500 "peacekeepers" that it could use. I can imagine an attack from Transnistria towards Moldova with significant support from Russia.
• Russia could try to annex Transnistria with Transnistrian government approving but Moldova trying to prevent that. I can totally imagine this happening
• Soft resolution criteria as pointed out by @DimaKlenchin 
• Russia is waging hybrid warfare towards Moldova more than in basically any places. This will probably intensify due to the Moldovan presidential election and a referendum about joining the EU later this year.
• Russian leaders are saying very similar things about Moldova now as they said about Ukraine before attacking it (Newsweek)

Factors that make Russian invasion to Moldova less likely:

• There doesn't seem to be enough troops in Transnistria for Russia to attack Moldova properly from there directly, and there doesn't seem to be any easy way to increase that number.
• Therefore, an invasion seems quite unlikely to happen without Ukraine collapsing, since that would allow Russian troops to enter Moldova. However, this doesn't seem very likely to happen in two years (~5%?)
• After Ukraine collapsing, it would take some time for Russia to start yet another war, so it seems like such an attack would happen outside the 3-year time frame of this question.

It is also conceivable that Russia would invade Georgia. However, it seems that the relations between Russia and Georgia are surprisingly stable despite Russia controlling over 20% of Georgia's territory. 

I don't see the invasion of Armenia or Kazakhstan anywhere in horizon, despite Armenia's ties with Russia deteriorating.

It seems very improbable for Russia to attack a NATO state, but I cannot completely rule it out, given that I thought the same for Russia attacking Ukraine. 

Finland and Sweden joining NATO makes an invasion to the Baltics even less likely, as this makes it more likely that the Nordic countries would follow up with a strong response.

Others have pointed out that Lithuania is the most probable target because of the strategic importance of the Suwalki gap, and I agree with that. However, I don't think this consideration moves the likelihood past 1%.

With over 2 years of the war in, and no attack with more than 100 fatalities in Kyiv by now, the base rate for this question is very low, especially given the extremely short timeline.

Passage of time