I'm at a tie between medic and tactician. I usually use medic most of the time to have the helper bot and the stand up ability. Now that I upgraded the tactician, I'm starting to enjoy playing as one. Having the ISA rifle is a plus.

The first couple days I had the game, I played the infiltrator almost exclusively. If you pick your targets carefully, you can stay in disguise for awhile and get a good amount of kills. After I upgraded the medic though, I been playing that a bunch in warzone. The 3 round burst assault rifle is so good. Add that to the bot and self revive and it's pretty sweet. Whenever I play operations and I am on defense, I always play engineer. Reminds me of when I used to play engineer a lot in TF2. Haven't really tried tactician or sniper yet.

I dominated in the beta using Infiltrator, however, since the game released, I've been doing horribly. Been having some great success with the Tactician now. His final assault rifle unlock is great! Next thing I'm gonna work on is the Medic, though.

Whenever I feel the need to defend an objective marksman is my favorite class. Other than that, I've been using the medic and engineer because they rack up points quickly.

I've been a sniper in all fps I play and KZ3 has probably my favorite sniper class ever.  Marksman through and through. Beyond that one shot one kill satisfaction, the silenced pistol is proving to be a awesome and fun to ambush people.

Tactician always but I'm going to slowly lean my way into Engineer as it's mostly unused.

Engineer all the way. By far my favorite class. Although I am enjoying both the Tactician and Medic on the side, their weaponry is too good to pass up. 
I don't have the patience for the Marksman and the Infiltrator just seems too specialized. I might get around to them one day.

tactician is fun because warzone, on top of playing through different modes, becomes one big game of domination. 

Engineer because I can repair tanks!... Oh wait....

medic!

i played engie in the beta.  still havent got my hands on the full game yet.  only a couple more days till finals are over.

" medic! "

Tact & Medic because I like helping my team, doing revives and capping spawns. Hopefully once the Medic gets patched properly we will see more people actually reviving.

" I'm at a tie between medic and tactician. I usually use medic most of the time to have the helper bot and the stand up ability. Now that I upgraded the tactician, I'm starting to enjoy playing as one. Having the ISA rifle is a plus. "

I started as a medic(and I sucked ass) but now I play as an infiltrator and some times as a tactician.

Tactician.
 
Knowing where enemies are is a huge advantage.

Engineer.
 
Closely followed by Tactician. I like controlling the battlefield. I like minions. I like working with the team. I suppose this explains my tendencies. :P

I played a lot of Tactician since release, but I have a group of people who I play clan matches with, and the importance of a medic cannot be understated for tight objective battles. 

Wanted to be maining as a engineer but the turrets have such low hp in kz3 that players can just stand still and shoot from point blank to get rid of em. first 6 unlock points down the drain :(
 
Cant decide between further unlocking engineering or swapping to the medic

So far been medic. Need to put some time in the other classes but I do enjoy the reviving as it makes it more of a team experience.

Started off with just Tactician... love that sentry bot. Now I'm going back and forth between Medic and Tactician, depending on what is needed more. Currently putting my points into Marksman, once he's somewhat upgraded I'll try him out.

Always prefer the Medic class when it is available. Hopefully people will start laying off the Respawn button after the patch. Don't know how many times I get ready to revive and the dumbass hits X.

The Medic.

Medic for sure, but especially in Warzone I sometimes have to play as tactician because nobody else is and you can't win without spawns. 
 
@EnemaEms said: 

" Always prefer the Medic class when it is available. Hopefully people will start laying off the Respawn button after the patch. Don't know how many times I get ready to revive and the dumbass hits X. "

I usually end up playing tactician most of the time because nobody on my damn team takes spawn points.

Tactician all the way.  In addition to the best weapon combo IMO (ISA M82 and rocket launcher) the drone lets you rack up assists to get the bullet damage ribbon.  Plus you're helping control the flow of battle by taking the tactical spawn points.  Not to mention the spot and mark letting you and teammates near you get the drop on the enemy.

Engineer. I also play as Marksman and Infiltrator, though.

Tactician, radar, shotgun and rocket launcher do me right. The bot's nice enough, but I'm really in it for knowing where enemies are and hitting them with an RPG. Ending an EXO pilot's good time is always a winner. Snagging spawn points is great too, 'specially when I get to start throwing mortars around.

I mainly use either tactician or infiltrator for most of the game.  I'll sometimes use marksman when were either really ahead or behind and I feel like sniping for fun and I'll use engineer if no one on the teams has set up ammo crates.  As for medic I think I used it only once because everyone always spawns before I get there.  

Medic. Second up is Engineer. 
 
Everyone that said Infiltrator: I hate you.

Engineer, and Tactician are what saved me from leaving the game. I couldnt do anything with the other classes, then one day i tried Engineer and the game was a lot funner to play.
  

Get your Portable ID!

Tactician.  IMO, spawn points win battles.  Engineers would be amazing though if they had an assault rifle with a red dot scope.  I can't go back to iron sights after using red dots.

Engineer or Medic

Tactician! 

Engineer, sometimes medic.  I like getting turret kills.  Getting harder to do as everyone levels up, though.

takes awhile to level up classes fully (pistol and all).  I've only jumped between marksmen and medic.  Wish I hadn't wasted so many points on the marksmen.

How do you find out if a friendly is actually an enemy infiltrator? That's the one thing I forget to keep an eye out for.

Tie between medic and infiltrator, usually depending on if I'm playing Warzone or Operations (Infiltrator for the former, medic for the latter) 
 
I'll play tactician at the start, and to take back the advanced spawning locations. 

" How do you find out if a friendly is actually an enemy infiltrator? That's the one thing I forget to keep an eye out for. "

Over this last week i've been switching classes during Warzone; i'll start off as engineer and fix as many crates and turrets as a can, i don't see a lot of friendly engineers these days, so we need those ammo crates! After that i'm switching either to tactician to capture any spawnpoints left or medic. I've been wanting to try out the infiltrator, but i wanted to upgrade his abilities first.