How many lines of code should one be looking at at any given moment? Of course you could zoom, but how many lines do you guys think is ideal?

Currently I have 33 when in full screen.

I have 55 lines when in fullscreen. I think it depends on how small you can make the characters without making it harder to read them. I find that big characters can get hard to read aswell. I would just play around with the font size and find my ideal size.

@Crapple no I mean like what would be too much?

I worked with an iMac once and that shit had so much screen, I started splitting my editor vertically and horizontally. It was nice to have four files open at the same time.

Anyway, I think the ideal is as much as possible, until you feel that it's too much and you could use the space for other things.