From the perspective of my one playthru Tav, Sava, I guess she got along with Astarion least, since they were two very different flavours of evil, selfish vs. habitual. They bonded over brutal killing, but fought over who wanted the book more, team building and about siding with devils and thieves a lot. This only changed about mid-act 3 when they reached some mutual respect and understanding.
As a grounded, middle-aged Githyanki, Lae'zel was a focus of both envy and sarthly instincts for Sava, as she came from a very prestigious crèche and had a bad tendency to rush into action without a proper plan. Sharing a bunk probably wasn't a good idea either. They broke up late in act 1, had a major fight over going to Crèche Y'llek in the Gauntlet of Shar and only truly bonded over the events there and their determination to help Voss.
Shadowheart fascinated Sava from the beginning, they started romancing in late act 1, and are now reported to share a farm with wizard tower in the lower Chionthar area.
Astarion, Shadowheart and Sava found Wyll before Lae'zel cage, so he completed the first Act I line-up as the token good character. Sava had decided that siding with the druids was the wiser choice, so having a local folk hero was perfect. While she didn't agree with each of his decisions, she respected Wyll's spirit and learning curve, so he remained a valued ally as we explored his past, pacts and every dungeon between the Wilderness and Baldur's Gate. But then, in Sava's view, the whole Ansur fiasco broke his mind. (I did this one just before Gortash and going to the Morphic Pool.) The Wyll they met at Reunion Camp may have just as well spent the time lost in the Wood of Sharp Teeth with Scratch keeping the "Blade of Avernus" safe from Ogres and Kobolds.
Gale had a bad start with Sava. Not only did she see him as wizardly competition, but he also burned through their magic items like Kobolds in a distillery. However, his sagely advice and solid evocation spells often saved the day, so the two became good friends and Gale a regular on the team.
Karlach completed the "girls' night out" line-up with Sava, Shadowheart and Lae'zel. This is the team that did most of the exploring, since their skills were well balanced and allowed them to pass most trials. When a quest was personal, a lock too hard to pick, an enemy asked for more arcane firepower or the situation required a hamster, the experts were called in, but this crew was the Gondian pocket knife. As Wyll, Shadowheart and Lae'zel descended to the riverside, they expected a tough boss-fight against what sounded like a Cornugon. It proceeded to become increasingly awkward, as first Wyll's file on Karlach fell apart at the binds, and then we had to admit that we already killed the jerks hunting her, because we wanted their stuff more. Karlach was the bubbling soul of the party, and I'm still hoping for a happier ending for her utilising the enhanced infernal metal. Shadowheart switched to camp duties after her parents were found, but Sava stayed with her friend Karlach until the end.
Call it a weak-spot for elves, but Sava fell for Halsin's charm early. He influenced Sava to take a road closer to the light side. I guess with Jaheira and Minsc there wasn't much of a change from my first impression to the last. Jaheira was, of course, invaluable when exploring Baldur's Gate, and Minsc was much needed comic relief when the end was looming. I only found out you could get Minthara as a companion when I was way past the Goblin Camp.
