These lists are tough, I admit. I've studied Russian Ds specifically, so I can't really speak for other Euro Ds other then the ones I've seen in NHL.
My list of Russian Ds come from imperfect information obviously, but it probably would be:
1. Slava Fetisov ... this one is easy
2. Valery Vasiliev ... I actually think he is underrated offensively, he had skills there also, but he viewed defense as his main responsibility and rarely ventured forward.
3. Alexei Kasatonov ... this guy would be viewed MUCH higher if Fetisov never existed imo. He absolutely had great 2-way ability. Keep in mind, it's really not easy to put up great numbers when your defensive partner is aggressive, yet that still happened.
4. Sergei Zubov ... I've said it before and I'll say it again, this guy is very underrated. The idea that he was one-dimensional is reputation only not reality. Great regular season track record, even better playoff career, I wonder if he would be a HOFer if he was Steve Zubnon from Ontario. Let me ask you all a question, Dave Andreychuk gets credit for his contribution as a role player on SC champion and what does Zubov get as one of the best players on 2 SC champions? Here is a trivia question for you, who led that famous '94 Rangers' team in points? Thank goodness they had Messier to "carry" them to SC.
5. Nikolay Sologubov ... ok, I admit, this one's tough. His competition is weaker, but even in NHL the competition isn't linear with so many changes that the league has undergone over the years. If you judge players based on their performance relative to their peers, Sologubov was one of the best of his time.
6. Alexander Ragulin ... similar to Vasiliev as far as offensive capabilities are underrated because he underutilized them. One of the smartest blue-liners on this list, his understanding of his position was off the charts.
7. Sergei Gonchar ... similar to Zubov, his reputation of one-dimensional Russian D followed him even when it was no longer the case. His Pittsburgh years were excellent, better then most player's peaks on this list. I can't speak on his Washington years, but something tells me there was more reputation then reality there also since according to most NA hockey "experts" physicality=defense.
8. Andrei Markov ... Russian. Good offensive numbers. Not very physical. This is a sure formula of a player who was a liability defensively, right? I wonder if there are any Habs' fans that are reading this. Oh, and regarding offensive numbers, do people even understand the difference in eras?
9. Vlad Konstantinov ... oh, what could have been. He still played long enough that I refuse to put other stay-at-home Russian/Soviet Ds over him. A lot of them had short peaks anyway.
10. Vlad Lutchenko ... tough to judge him on numbers and awards, but he was absolutely considered among the best of his time. He showed flashes of offensive capabilities, but it's his defense that has him on this list.
11. Vitaly Davydov ... Among the best of his time, he was also similar to Lutchenko, capable offensively, but defense-first. This actually seems like a theme with Russian Ds pre-1980s. I think it has a lot to do with the scheme, rather then the talent. A lot of these guys played with great forwards, or all really, less of a need to be aggressive.
12. Dmitry Yushkevich ... a lot of his career was marked with injuries and inconsistency, but those seasons with Toronto, boy... He was one of league's best in his own zone, unfortunately briefly. Just ask Jagr if he was easy to play against, they had some heated moments.
13. Viktor Kuzkin ... the leader and the rock of both CSKA and the NT, he was not flashy but was relied on heavily and was a big part of very successful teams.
14. Ilya Nikulin ... this is going to be HIGHLY controversial, but I am very high on this player. He was one of the leaders on 3 WHC gold medal teams (also has a silver and a bronze, plus 4-time league champ). I know those tournaments are viewed as second-rate, but the competition is far better then given credit, PLENTY of NHLers and talent in general. He was even the Captain on the 2012 WHC gold-winning team, making into the tournament's all-star team. Physical puck mover with high IQ, in his prime, he was one of Russia's best. He absolutely deserves better recognition, his trophy case rivals most Soviet guys.
15. Ivan Tregubov ... a bit overshadowed by the more highly-touted Sologobuv, Tregubov has a strong legacy of his own. Again, we are judging this based on performance relative to peers.