I always commend Someone, and I figure tanks and healers already get most of the commends if for no other reason than being on the top of the list, so if I don’t have a preference of a specific person I tend to commend a random dps. If nothing else dps getting less commendations makes them go oh cool more likely when they do.

Of course with the way roulettes and dungeons work, it’s also often whoever took two seconds longer to sprint to the exit and was still available as an option to commend.