Worst regular bug I've encountered is the one that makes autosave files not load. I suspect this might be related to overlapping autosave triggers (I also experienced all three of the last autosaves being for the exact same "moment")
Did have a few other errors - one point the game did put the characters offscreen (but showed it anyhow) in the lead up to a Tempest Landing cutscene (but thankfully loaded the cutscene and then loaded the characters back into the environment properly). And at least once on Kadara after starting the outpost, the oupost didn't load so people were sitting in the air for a minutes until the buildings exteriors/layers finally popped in.
Biggest quest related bug I've had is one triggering the completion dialogue before I'd completed the quest making the quest uncompletable.