The only gear I've repeatedly farmed a dungeon for was Brayflox because you didn't need to upgrade until around Stone Vigil (lvl 41). Brayflox was farmed before the dungeons gave decent xp, if that gives you any indication of how good the gear was. Pink items just serve their purpose to get you to the next tier.

At lvl 45 you get your class artifact gear (minus chest piece). But honestly Dzemael Darkhold set is better and sometimes nicer looking, depending on your class. It's not uncommon to see new players with their artifact gear and the Darkhold chest piece all the way until 50. Once you hit 50, you get a full left side set of i90.

The only dungeon drops I would worry about getting, are the greens from Brayflox and Darkhold. If they're way below your lvl, don't worry about it.