Here's my favorite Obsidian games in descending order:
1. Alpha Protocol 2. Tyranny 3. Neverwinter Nights 2 (and expansions, especially Mask of the Betrayer) 4. The Outer Worlds 5. Pillars of Eternity 2 6. Pillars of Eternity 7. New Vegas, I guess
The first two, especially, are among my favorite games of all time.
Well the only respectable thing about this list is putting Tyranny high.