While it's technically part of the UI itself, the Quest Log/Journal is the absolute worst of the worst. This isn't 1995, this isn't 2004.. this is 2013. Lemme give you an example here too...

WoW - My quest log is MINE. I can pick what quests I want to track, have them pop on the map upon tracking, sort them in about 10 different ways, including difficulty, level, zone, dungeon, group etc etc etc. WoW is over 8 years old at this point, and has one of best functioning User Interface ever.

FFXIV - None of the above. You can't even choose which quests to track. Once a quest scrolls off your menu, it's not coming back unless you complete everything you've grabbed since then. Leaving a map and grabbing quests TAKES OFF ALL THE MARKERS from the map if it's not actively tracked on the game screen. Who the HELL thought this was a good idea and approved it?!