The Nineties saw Warhammer Fantasy Roleplay as the generic RPG in Poland, as opposed to D&D. It is not so nowadays, though, with the appearance of new editions of D&D and a new generation of gamers. That is, gaming folk still will recognise it, but it's not as dominant as it was.
WFR is still considered the generic RPG, some folks even go as far as marking D&Dnot an RPG.
Blood Bowl is a "Specialist Game" in most countries, with miniatures available but not usually in stores and not pushed as much as the trinity of Fantasy Battle, 40k and The Lord Of The Rings, but in Germany it is considered one of the core games and tournaments are still held there.
Thanks to having been for quite a long time among the few foreign RPGs translated and published in great numbers, Call of Cthulhu is quite well-known in Italy together with the aforementioned Warhammer Fantasy Roleplay. As with the Polish example above, this is mostly true with older gamers nowadays.
France also has had a long love affair with Call of Cthulhu, in this case despite the fact that lots of foreign RPGs have been translated into French since the 80's at least. It seems to still attract new gamers there as well, as recently, a publisher there released over a dozen superlatively translated, beautifully refurbished (if expensive) hardcover volumes of the rulebook and many of the most iconic adventure compilations and setting books, including a 30th-anniversary edition of the main rulebook as well as Delta Green and its rare-as-hell-in-English expansion, Countdown!!!
Vampire The Masquerade also had, and largely still has, an enormous popularity in Italy, with several running LARPs and a widespread rejection of the New World Of Darkness system in favor of the old game. Since Vampire was the only old WoD game to be translated, this leaves its sister games (Mage, Werewolf et cetera) pretty much unknown.
Privateer Press's Monsterpocalypse sold out world-wide within a week of its release, but nowhere did it sell faster than in Japan. Given that it's the country that madeGodzilla, Mazinger Z, and Ultraman, it's hardly surprising.
Warhammer 40,000, while still decently popular in its homeland of Britain, really took off in the United States, completely displacing Games Workshop's previous works in much of the American tabletop wargame market and providing fuel for large numbers of books and a number of computer games, most with American authors and produced by American companies, respectively.
In-Universe Examples
Rocky, one of the Emerald City Sentinals in the Emerald City setting of Freedom City, is a Former Child Star who spent most of his career after his show ended touring Japan, becoming moderately popular there as a result. In fact, his character sheet has "Benefit: Status (Big In Japan)" as an actual character trait.
