To me, PoE is an infinitely-replayable RPG, not only because of the quality of its storytelling and the intriguing depth of its setting, but also due to the incredible variability in gameplay experiences depending on the class the player chooses. A playthrough with a Fighter PC is substantially different than that of a Cipher, right down to the class-specific dialogue options that one is often presented with. I'll always have to remind myself to put more points in Resolve next time, though.