Talking about Russian in Ex-USSR. I was born in USSR,5 years before the fall . Before moving to Romania I think that my Russian was like the 2nd mothertongue,now I have some problems when it comes to write it.
For example in Moldova,Russian is wide spoken,especially in Kishinev(the capital),where although Russians are 15% on the streets you hear more Russian than Romanian,I'd say 60-70% Russian and 30-40% Romanian.In the villages ,Romanian is spoken more than Russian. There is a certain language in Kishinev and in big cities that young people use,some hybrid between Russian and Romanian,based on Romanian grammar. For example: Blin am paterit nomerul de mobilnik al tiolchii cu care am bazarit cherez skype .Damn ,I ve lost the mobile number of the girl with whom I talked on skype)
In the villages , there are people who aren't fluent in Russian (believe it or not those are people older than 60 yo). Nowadays many young people in Moldova are fluent in Russian because all the movies they download from internet are translated in Russian,cinemas in Moldova are in Russian so are the books in library,people watch Russian television,especially Comedy Club and shows like that.
Of course some Moldovans make mistakes in Russian, and some sort of Moldovan accent ,although not so strong as the Baltic or Caucasian one ,exists: for example Sofia Rotaru speaks Russian with Moldovan accent.
However,people here are generally positive towards Russian . Another interesing fact : in Molodva 1 Russian and 5-6 Moldovans will always speak Russian.
The problem is that many Moldovans,although they can speak Russian very good,they write it like kids in the 2nd grade. Палатенце instead of полотенце and so on. And this is the case of young people who didn't learn Russian in school,but in family,on the streets,television.

As for other nations of the ex-USSR ,I'd say Ukrainians speak Russian very good,Belarussians,Kazahs and Armenians.Estonians on the other hand speak Russian very bad.

I haven't meet people from outside ex-USSR able to speak Russian very good(except for those who were born in USSR and emigrated ).