diablo-3
I can't get the reset quests button to show up on my wizard, which means there is a quest I haven't completed yet. However, when I go to game settings, it allows me to choose every quest in every act which kind of implies I've done them all.
The only resource I can find is the Quest Aggregator, which says I haven't killed Belial yet, but I have, many times. However the quest reset button just isn't there.
What am I missing? How do I see which quest is still marked as incomplete?
No, they don't reset. What you're experiencing is a bug (that is, as far as I know, still not fixed) where achievements don't get transmitted to the server correctly and thus disappear again after starting a new session.
For example, here's a section from a news article about it:
Those users lucky enough to make it in have reported quite a number of issues. One which is drawing particular ire is the apparent loss of achievements, although responses in a Blizzard forum thread on the matter suggest the servers may just be playing catch up; the developer noted that the achievements server is getting hammered.
UPDATE: As of Diablo 2.0, this is no longer the case. The difficulty can be seen in the top right of the screen, next to the clock, while playing.
The only way I'm aware of is at the character select screen:
You can change the difficulty (assuming you've unlocked them) by going to the Select Quest screen, and changing the difficulty of the quest you're going to start.
Best Answer
There are some minor hints in-game:
Using these I was always able to finally track down missing quests, but it is far from convenient.