I haven’t been able to play the game too much because of some technical issues I’m experiencing, but so far I really like the Acolyte/Necromancer and the Primalist/Shaman (I could be wrong on that subclass name, the one with the totems).
What are you guys playing and/or enjoying? 
I’ve played Acolyte, Primalist and Knight. By far I’d vote Knight.
Mage using Static Orb based around Shock Nova’s is grand until you start breaking the client (sound desync, crashes every so often 
)
Have you guys tried out the new frost spells with the freeze mechanics? Freezing things is always fun
But really… always meteor!
My favourite so far is Necromancer. But I can see Warlock being my main eventually.
I don’t know man. I played too much Azula in D3. Kinda burned out of playing mages haha
I’ve played some of everything so far and I’d say my favorite is either Mage-Sorcerer (working on a post for that) or Knight-Void Knight (because Echoing is very fun to build around), with Primalist-Shaman close behind and Acolyte-(anything) a distant, “I haven’t figured out where the fun in this class is yet and I think they might not be up to snuff” last place.
I’ve been hearing about this Echo thing from a lot of people, I’ll have to try it sometime. I still need to try a lot of things :S
I’m with you on the Acolyte/Necromancer. Been a life-long Necro player so naturally ours is the one I like the most. I believe we’re going a great direction with it!
Shapeshifting Druid:)))
The strongest so far is definitely Void Knight spec. The health leeching and any Void damage spec does great damage (hammer throw, tempest or the crazy Orbs).
However, my favorite so far is Lich build that focuses on spamming Souls and using Wandering Spirits to shoot poison. It’s so crazy on the screen!!! Love the homing souls.
The one I don’t enjoy is Sorcerer. Huge mana issue. No survival.
Disclaimer: I only been testing builds for a couple weeks so i’m still a newbie. This is my experience so far, I have tried: shaman, necromancer, lich, void knight, sentinel and sorcerer.
My favorite build/class so far (i’m personally surprised by this) but it’s Knight. Knight has super explanatory survivability in VK with leech and when you spec it that, it feels like you are free then to explore all the other things Knight as to offer from different class tree layout to different skill specializations. Everything in Knight seems fun and viable so far.
My least favorite is between mage and necromancer. The game play to both is actually very enjoyable. I enjoyed shooting things with lightning and watching them get zapped on my mage; it was a nice fast pace playstyle and I liked the aesthetic of necomancers minions/creating my skele-army!
My disappointments from the classes came when I entered aren. I feel like Sorcerer has limited ways of survivability. I really don’t understand how to fix it. The only option it seems is to either kite and kill them before they kill you (which is hard without really good gear) or focus on wards. I don’t think wards in the class protect you enough. I felt “boxed in” when playing the class and not sure what to do to fix it.
I also enjoyed the game play of necromancer also but I found the pets died so fast, like instantly; even with a lot of minion mods on your gear. Players have told me necomancer becomes strong later on but I felt like I didn’t want to wait for that to happen. I wish there was an easy way for you to have a lot of skeletons in necromancer and also buff them like the wolves in Shaman. I felt like playing a hybrid totem/minion build was so much more enjoyable on that class than it was for my necromancer.