I use the default ASCII. Graphics packs have too much graphics. The less physical graphics a game has, the more you can imagine yourself. IMO, computer graphics are for people without the willpower to use their imagination. Sadly, pretty much every single commercially distributed computer game since at latest 2000 targets only these people, because there are just so many more of them and because graphics are much easier to make than to inspire. Even sadlier, most people seem to have forgotten that there exists such a thing as imagination, because they never need it to play their computer games.
IMO, computer graphics help for it to be easy to use.
...........;...,.....
....'.......'......;..
..;.....

........,.
...."........,..."....
Without knowing what those ASCII characters mean, an image of grass with a dwarf looks way easier to use.

^ That there would be way more complex looking without graphics, but here it looks more simple and easy to tell what everything is.
I often switch between ASCII and graphics.