Great so far, although I've just made it to the end of Season 3. I've got a long way to go, I know. But for now, I'd rate it S3>S1>S2.
Two being the weakest because of its very weird pace. Some episodes have you on the edge of your seat, while others have you, well, not so much.
The first season was excellent. Good world building, great character arcs, etc. Acting was well done.
Third was also excellent, albeit the finale (It was fine, but disappointing in more than one way.) Most episodes were back-to-back exhilarating.
Looking forward to Season 4 when I get the time to binge again.