One of the nicer touches to JMS's worldbuilding of the Babylon 5 universe is the fact that many of the alien species, and even different characters within the same species, speak with different accents (unlike in a lot of English-language sci-fi where pretty much everyone has a British or American accent no matter which galaxy they're from). We've got Delenn with her Croatian-influenced accent, Londo with his part-Czech, part-Irish accent, but not all Centauri speak in the same way, as you can see in this scene:
Lord Refa always reminded me slightly of an Italian mafioso, but I'm not sure if that's an accurate description of his accent. What accent is William Forward (the actor) using for Lord Refa?