I like most of the sounds in the game, I think the Legacy sound guy did a good job overall. The game sounds are overly loud though and I play with my volumes at around 10% unless I'm in chat with friends then I have to turn it down even further.
Some sounds I find truly annoying; MM Bots stomping around and Demon rawrs, the portals in PI, Spines and Fire auras to name a few. Some I silence outright other I modify. I reduced dog bark volumes by 80%, Demons giggle like infants, Bots squeak like rubber duckies, glowies cackle like pack of hyenas.