So I've been playing WoW for a few months now on my Pally. I like my Pally, but I decided it was time to start and alt. My Pally is fun so I don't intend on a new melee class, I want a caster. So now I ask: Spriest, Lock, or Mage? Which is more fun? Which does the most damage? Which is easiest to play? And which is best for PVP? THANKS!

For PvP if you like to kill stuff def go mage because they are very OP at the moment.

Although Priest has the ability to go shadow or you can go Disc or Holy and have the ability to be a healer and adds some spice to the class.

Warlocks are meh right now, your seeing a huge decline in them because they arent to good and die pretty easily.

As for PvE any will work it just depends what kind of gameplay you like.

Although i can tell you from personal experience from having played each class, the ability to heal yourself and not be totally helpless to incomming damage is really nice.

I love my shadow priest, my boyfriend plays a Lock and our best friend plays a Mage lol. We all argue who is best. I hear Spriests are kinda confusing, we have lots of moves and use mostly DoT, and for raiding/instances it gets hard because we really only have 1 AoE and it's not very good....at all. At the moment, spriests are gimp. But we are getting a bit of a nerf next patch.
Mages and locks seem to always be fighting for top. In the next patch, frost mages are being nerfed as well.
I'm not sure about Locks, but Mages and priests are SQUISHY! They get hard to level because we can only wear cloth armor.

I would check out WoWhead. That website is AMAZING. It gives a summary of all the classes, and you can sorta get a feel for them before you make them.

LOL u pick the op classes much? haha anyways so ima hardcore pvper take arena an etc seriously but as of now for the 3 classes so wat u would do is Spriest AFFLICTION lock or frost mage honestly there nerfin the P.I.S.S out of frost supposely so dont go mage now between locks an spriest its very iffy if u get a nicely geared affliction lock an he dots up all the oppents in the arena match an keeps the dots up they do VERY good damage plus u got too many fears an a demonic portal thing so when an enemy is to close u can jus teleport away an fear an dot em haha so say u got lock? do affliction an ull find arena being VERY easy well aslong as u can play an u have non tard partner/partners. now for the good ol spriest spriest is a very fun / easy/ retarded op class too hahah anyways so lets look at some moves u got a fear then another lil fear but mainly for its disarm good against melee fear em + disarm ftw? very good hard hittin dots then u got mind spike so mind spike + mind blast hits hard as hell lol u got mindflay which is a channeled cast that does dmg + makes target move 50% slower then u also got a move called paralyis which is a talent in ur tree that makes em like snared (cant move) or watever for x amount of seconds then u have there little doppelgangers that spawn an they walk to their target an blow up an srry this is to long so ima stop there but hopefully this is just wat some of the spells can do haha, honestly do this go to youtube an type in affliction lock arena cata or spriest arena cata an MAKE SURE the person is actually good an can play haha an see wat u think ull like best? (could also make a PTR chars copy a priest over make em shad an also copy a lock make em afflic then do bgs an wat not on PTR)