Well, hello Gorth. Nice to see a familiar skull...
I was a tad too young for RPGs when SSI released classics like Curse of the Azure Bonds and Death Knights of Krynn (I was 11 years when DKoK was released though, so, maybe I could've started there but oh well).
Of past and present:
1. Black Isle
2-4: Bioware, Troika, Obsidian