Kinda hard to say - we all speak similar languages
Albanian is different, that's (along with Hungarian) only language that was spoken in ex Yugoslavia, but is not Slavic. I speak Croatian, Serbs speak Serbian, etc...but even on some slavic studies in the world you will find term Serbo-Croatian. That's not completely fair, because although those languages are quite alike, they are much more different then some Scandinavian language for example - and you never hear term Swedo-Danish, or Swedo-Norwegian
(Slavic nations:
Eastern Slavs: Russians, Belarussians, Ukrainians (all three languages are pretty much alike).
Southern Slavs: Croats, Serbs, Slovenes, Macedonians, Montenegrians, Bulgarians (three groups - similar languages are Serbian, Croatian and Montenegrian - Bulgarian and Macedonian - Slovene is different then both groups).
Western Slavs: Poles, Czechs, Slovaks, and one very small group that I don't know to translate - "Luzicki Srbi" (Srbi is Serbs, and Luzicki is from some area in Western Europe, but I really have no clue where)
drom - cool, I'm sure nobody so far thought about me in Bordeux