I've played Nethack as a researcher trying to find out what makes it good. Of course I've played Nethack even before I started Kaduria (a long, long time ago), but I need to try different professions and also try to become a better player.
The biggest problem in Nethack is Elbereth which kind of fixes an inherent design flaw. Also in my opinion D&D has always been "broken", because it relies too much on magic. But even if the game seems to be broken it can actually create a gameplay that many people seem to like. And it's not fair to judge game design that was created mostly in 80's by regular students. In that context Nethack has stand the test of time very nicely.
Angband is another game I need to study more. I never liked it and didn't even want to learn how to play it. It's still difficult, because the user interface is really bad and tries to scare you away. I remember the old Angband was better (one with true 80x25 console). What they have now is way too many tilesets while they should concentrate creating one good set and ascii modes are also poor, with bad fonts. It's sad how the UI can't even scale to selected font size, you have to increase or decrease the tile size manually.
It's been really warm for over a week now. 25+ C which is extremely warm in arctic region. I'm trying to survive days at work and when I get home do nothing. It's hard to concentrate on programming so I have spent this time playing (or researching as I call it).