No real favorite variety. I occasionally play solo, but generally I play coop with a friend for a full weekend at a time every 3 to 6 months. So if it's fun and supports coop to some extent, then it meets my pseudo requirements. I love good game play, it's something of a necessity to enjoying the wad, but I must confess to catapulting my underwear elastic across the room over some good eye candy from time to time.
1. Eternal Doom III (classic, great for coop provided you don't die in particular areas & break the level)
2. Requiem (amazing for coop)
3. Herian 2 (great coop & impressively, it was a one man project)
4. Ultimate Torment & Torture (great coop & love the visual mood of it)
5. MikeDMC1 (Feel free to laugh. Haven't touched this one in years, but it was my guilty pleasure map for most of the late `90s.)
I should probably be smacked for this, but I also tend to cheer for the procrastinators of Biblical proportion. Yup. I still check for Mordeth updates from time to time.