1. Mages can summon infinite food, water and mana potions. Starting at a very early level, mages get the ability to summon food, water, and mana gems that are equivalent to vendor-bought food, vendor-bought water, and mana potions. At the maximum level, mages can summon food and water in one item, allowing them to save inventory room. This is incredibly useful for any and all aspects of the game, as everyone needs to eat and drink after most fights.
2. They are World of Warcraft's best nuking class. Mages are the ideal nuking class and are by far the best at it. A few other classes have specializations that make them a nuking class, but they do not compare to mages. Mages have a large arsenal of spells and abilities to pump out massive damage in a short amount of time.
3. Mages are the only class that is able to cast teleportation spells. Other than Druids being able to self teleport to Moonglade, which is a pointless location, mages are the only class able to teleport. They can teleport both themselves and their party/raid. This is not only a bonus as far as faster traveling is concerned; but it also allows a mage to set their Hearthstone to a non-city location.
4. They have three very useful specializations. Mages can specialize as fire, arcane, or frost. The raiding/DPS specializations are fire and arcane, both of which bring different aspects into DPS'ing. The frost spec is great for PvP, as it gives the mage incredible amounts of survivability. Most mages find themselves respec'ing frequently to test out different styles of playing.
5. Mages are the best Area of Effect damage casters. Most mages will level by AoE grinding. This is where a mage will gather up a large amount of mobs and use their AoE spells to mass-kill, granting them a large amount of experience in a very short time. Mages have many different types of AoE's, ranging from Blizzard to Blast Wave to Arcane Explosion.
6. They are one of the easiest classes to level with. With the above reasons, mages can level to 70 very quickly, very easily, and very efficiently. With infinite food, water, and mana potions; powerful AoE spells; great survivability; and incredibly fast traveling; they can level in a very astonishing short amount of time.
7. Mages are the game's best burst damage dealer. At the beginning of a long fight, mages can deal thousands of damage per second. They have many cooldowns to use and typically have very powerful trinkets. When combined, the outcome is a very high amount of damage. However, when their abilities are all on cooldowns, their damage output slows quite a bit until the cooldowns finish.
8. They are highly sought after for Groups and Raids. Because of a mage's ability to summon food and water, they have the game's best crowd control, and have high damage output; they are highly sought after for groups and raids. There are always at least two to three spots in a raid for mages, if not more. And almost all groups try to recruit a mage to run through an instance. As a mage, you will never have problems finding a group or raiding.
9. Their damage scales well with gear. Some classes are terrible with poor gear and gain lots with better gear while other classes are great with poor gear but do not gain much with better gear. Mages are special in this situation, as they are fairly decent with poor gear, but improve noticeably with the addition of better gear.
10. The Frost talent tree is one of the best for survival in PvP. A frost mage is one of the hardest classes to kill in PvP. They have an incredible amount of escape abilities and protection abilities against both Melees and Casters. They also have the ability to instantly refresh every one of their cooldowns, making them doubly as difficult to kill. If you enjoy PvP'ing and being able to self-sustain, then a mage is perfect for you.
