Soooo this turned out way longer than I intended and English isn't my mother tongue so I might come off as confusing or something but here goes:
A DS Sith Jugg Immo was my first character and overall it was a great experience both story- and gameplaywise. Corrupting Jaesa was good fun, but chapter 2 starts bad, but luckily the story picks up again quite quickly. Animations were good-looking, loved backhanding giant droids, rancors etc Ravage's animation had me smiling often, it just looks so brutal, like he was wielding a two-handed ax or something hahah and so not a lightsaber. In contrast, I was disappointed how the dual wield ravage looks, but Sentinel's master strike looks very, very cool. Odd things to 'complain' about I suppose, but for me it's the details that count.
My second char was a gunslinger. Prologue and chapter 1 were great fun and the slinger action was a welcome change after tanking through the warrior storyline. Buuuuut then chapter 2 happened and I also realized that ranged dps doesn't seem to be my cup of tea, so I'm considering rerolling a scoundrel healer (I'm under the impression that leveling as healer is a pain, but I've never tried it so who knows)
Purely from a gamplay pov, I've had the most fun as an AP Powertech. Lots of mobility, nice skills and great animations. Damage is pretty good as well, but aoe seems lacking. Chapter 1 was good, 2nd a snoozefest, but ch3 is good stuff again (finished Voss last week).
IA - kept hearing how amazing the story is and made an Operative. Chapter 1 was pretty straightforward, but good fun nonetheless, ch2 was great and I'm currently on Belsavis with him. The devil is in the details and the IA story has had the best to offer in terms of shades of gray, which I've enjoyed greatly. The Operative gameplay is ok for me, nothing wooooow, but doesn't make me cringe either.
SI - wanted to love Sorcerer so bad, but just didn't enjoy the gameplay. So I rolled an Assassin and made through the story alternating between dpsing and tanking. The gameplay felt kinda tedious as an Assassin too, but overall it was ok. Storywise playing an Assassing felt *so* all the way through that I made a new Sorc last week just to shake the feeling hahah. And to give Sorc gameplay another chance naturally. I saw some Sorc in action on lvl 40+ and it looked so flashly that I might be able to push through the beginning again
Storywise I liked the feel of it very much, but there was way too much foreshadowing for it to be surprising.
I also made a Trooper Commando (lvl 29 now I think), but I'm not feeling neither the story or the gameplay