Ahhh this is literally one of my absolute favorite video games.
I’m currently on my 4th playthrough (I’m at like 676 hours total time played at this point)
I literally had watched and waited for the game before it even came out, back when the initial announcement trailer was released, I believe. And as soon as it came out, me and my dad both got the game to start playing and discussing it, and it lived up to every expectation.
I honestly don’t even know! I love all of it sooooo much.
I love all the characters and their storylines, and the gameplay is fantastic, and just everything about it!
One of my must dos for every play through is to (act 1 spoilers) bring both Scratch and the baby owlbear to camp! Cause I need these cuties in my camp no matter what.
It wasn’t instant regret, cause I didn’t know it until it was far too late… but in my second playthrough I missed a cutscene/important interaction with astarion in act 2… then after I was in act 3 I realized I had accidentally locked myself out of progressing the romance any further…
Astarion and Shadowheart!
Astarion is certainly my favorite companion so even when I’m playing as a rogue too, I still have to have him in my party.
Shadowheart, I adore her as well, but I always need her in my party to be a healer especially.
The 4th member of the party would be interchangeable based on how I’m feeling at that point.
Though, on my current (4th) playthrough, I’m finally trying using mods for the first time. I’m only using a single mod, but I’m loving it. It’s the adjustable party limit mod, so I can bring all of the companions with me everywhere and it’s been awesome.
I have to say Astarion.
(Spoilers) I can’t kill Cazador soon enough. I’ve never done ascended though. I always leave him as a spawn. Plus, I have a bit of a thing for vampires, and I can’t resist him 
I do love each of them though, but his storyline squeaks out at the top. (And I’ll 100% admit that he is one of the sources of inspiration for the mmc/love interest in the novel I’ve been trying to write)
Good or good but slightly morally grey.
I still haven’t been able to bring myself to do an actual evil playthrough yet, but I will eventually.
I’ll add info on my characters tomorrow.