Meh, I personally wouldn't really want a DmC anime, as I just don't find anime-aesthetics to really fit it (don't get me wrong, I actually like anime, but not really on DmC).
Apart from that, I prefer it if they explain things in-game, instead of explaining it in supplementary material.
But if we'd just go with the thought of them making it into an anime, I'd kinda like it to play before the events of the game, exploring Dante's life when he was, dunno, 16-18 maybe? I've just kinda got that headcanon about that very first trailer that was released back in 2010, with him still smoking and being held captive and seemingly tortured, to be what had happened when he was 16-18, so, yeah, that's something I'd like to see ^_^