For me, and I know it's different for other people, but I always preferred Obsidian games over Bethesda ones. That's not to say that they're my favorite dev ever or anything. But aside from Morrowind (which I loved) and Skyrim (which I liked a great deal, although it did have some issues), pretty much anything by Bethesda has just felt meh to me.

I hate to say it because they're really good at making worlds that feel alive. And of course I will always love Morrowind. But I feel like beyond that they're just kind of... there?

Meanwhile Obsidian gave us New Vegas, KoTOR 2, PoE, and Alpha Protocol, all of which I liked (to varying degrees).

That's my take on it, anyway. Obs not everyone feels the same

As for BioWare. I liked their older stuff (KoTOR, Baldur's Gate II) quite a bit but I haven't really been able to get into any of their new stuff. I don't know if they're really the dev for me. In fairness it's been a little while since I've given them a shot, I guess.