You may notice that some quest rewards include not just XP and currency. A few quests grant gear of various tiers. If you want to plan around these quests, below is a list of items, by type and by tier, that are rewards from quests.
Please post corrections or additions to this thread, and I will try to keep this list up to date.
By Tier
T2: Helmet
T3: Cloak, Gauntlets, Boots
T4: Weapon, Chest Armor, Boots
T5: Helmet, Cloak, Chest Armor, Gauntlets, Leggings, Ring
T6: Weapon, Chest Armor, Boots
T7: Amulet (with T3 gem), Cloak, Ring, Helmet
T8: Leggings, Chest Armor
T9: Amulet, Cloak, Ring
(T15: Ring°)
By Item
Helmet: T2, T5, T7
Amulet: T7, T9
Cloak: T3, T5, T7, T9
Chest Armor: T4, T5, T6, T8
Weapon: T4, T6
Gauntlets: T3, T5
Leggings: T5, T8
Boots: T3, T4, T6
Ring: T5, T7, T9 (T15°)
Shield/Off Hand: none
°tier 15 ring from quest line linked to Shattered Plane. Some assembly required.