Which Slavic language should I learn?

I am Albanian and I personally think that Russian is a very beautiful language and my father speaks it fluently since he learned it in the school during times when Russia and Albania were very close communist allies. I don't think that it is as useful as English and German or Spanish these days, but if you read Toltoy in Rusian, only then you can understand what he really meant.

I like Polish a lot. It sounds like a mix of French with slavic.