As in, among NATO or NATO-aligned nations? Finland of course has had Soviet/Russian military equipment for ages and Israel at one point took whatever they could get their hands on but those are special cases.
I am meaning countries like France, the UK, the other Nordic countries, Netherlands, Australia, New Zealand, etc. Did they ever contemplate things like, for example, the Mi 26 heavy lift helicopter as an alternative to the Chinook or Sea King? Or did any consider MiG/Sukhoi fighter jets as opposed to Dassault/Boeing/Lockheed/BAE(its forebears)? Or the T72 tank? Or the NSV machine gun? Anything the Soviets/Yugoslavs had that had a western equivalent?
As far as I am aware the answer is no. The Warsaw Pact weapons would have been incompatible with NATO standardization agreements, which were matters of serious military and political consequence. Conceivably a T-72 firing 105mm or 120mm NATO ammunition vice Warsaw Pact 125mm could be built, for example, but this would have been a headache. The matter of sourcing spare parts would also have been essentially insurmountable.
Further, even if the French developed a sudden longing for the fruits of the Kharkov Design Bureau, the Soviets had every reason not to sell. NATO went to great lengths to get technical intelligence on Soviet weapon systems and vice-versa. The US Military Liaison Missions in East Germany, for instance, engaged in James Bond-esque spying missions to try and sneak photos and up-close looks at the equipment of the Group of Soviet Forces in Germany, complete with frantic car chases and on one occasion, the death of an MLM officer from East German sentry rifle fire. So then you can see why the Warsaw Pact would not willingly give this information to the enemy.