Quest rewards are often a thing of torture. Players are able to get much benefit when you have completed quests. It is including XP, items, equipments, and WoW currency etc. The reward is sometimes gratuitous giving you only cheap WoW gold or potions. Sometimes it gives you a multiple choice of items. These items then taunt you. Which one should you choose? If you are lack of gold, but don’t want to Buy WOW Gold, I think you choose rewards WoW gold. Quest reward may vary. Most quests take before the level cap gives experience as a reward. With the experience most quests also provide a variety of rewards. Second, most of quests also give reputation if they are given to you by an NPC of the faction significant. Rewards can also be in the form of reputation only, honor, or unlocking instances.
The difficulty in choosing the reward often comes when you are faced with multiple choices that match your character. Some items are obviously not going to work because you cannot empower them or their statistics do not in any way help you. For instance, a Rogue can't equip Mail or Plate so those rewards are useless. A Rogue also can't really get much benefit (wow gold) out of spell damage and intellect so Cloth and Druid leather are out of the question. So obviously for the Rogue any kind of quest reward that grants Agility, Stamina, Attack Power, Critical Strike Chance, and any other melee orientated stats will be the best choice.
Additional Rewards
Texts add 100 rep per 10 turned in, on my server the usually go 20g/stack of 20. you can, as the OP said grind rep from the twilight guys (1 per kill, up to 5 for the 'twilight keeper' mobs) and collect the texts off them. Turn in 10 texts and you've got a nice chunk of rep.
After you summon the Templars from the Lesser Windstones (the ones that need just the robe/cowl/mantle. also noted you can usually Duo these, get a tank and a healer and you're set.) you can turn 3 of the Crests in, along with a Large Brilliant Shard, to get an item to summon Dukes. Dukes get summoned from the Regular Windstones, and require the mantle/cowl/robe and the necklace you got from turning in the 3 crests and the LBS. they can usually be 5 manned, and you will need a warrior to hold aggro. Dukes have some very interesting loot, Soulrenders are popular for Hunters/DW Fury Warriors, etc. Dukes give roughly 25 rep per kill (i think). you kill 3 of them, with each kill you get Signets. these Blue items can be turned into CH, along with 5 LBS for a ring to summon Lords. Lord summons require the mantle/cowl/robe, the Neck from summoning the Dukes, as well as the ring you got for turning in the 3 signets and the LBS's. these lords require 20-40 people depending on your guild's skill level and gear level. they drop some REALLY good epic quality items, one per type (Fire drops a caster ring, Water drops a healer neck, Wind drops a DPS cloak, and Earth drops a warrior shield.) these, when killed, give 50 rep (i think) and give you an Abyssal Scepter. These get turned in for rep as well, and I don’t know how much of it. Also, if your server has opened up AQ, AQ20 is a good place to get rep. The bosses give 100 CC rep per kill, trash mobs give 1-5 per kill, but there’s a lot of trash in there. so if you've got a good guild together, tear up AQ20 for some fun rep grinding.
Most importantly, save quests for when you're Honored or Revered, same with texts. Like this, players can get the cheapest wow gold and the best WoW rewards in the game. Grind the trash in Silithus until they don’t give rep any more, then turn in those texts you've been saving as well as the quests you've been saving as well.