INFPs aren't Si types though, and this only argues he is a sensing type if he characterized more by a sensing function. I could see ISFJ for him over INFP too, being that he is too earthy to be an INFP. I don't see Ne...being playful & sometimes using wacky analogy is not Ne, and it can be how inferior Ne plays out (in humor or when frustrated, not as a life strategy). I realize he is e9 and people think e9=INFP.
The only reason I'd go with ENTJ over INTJ for him is because of appearance of inferior Fi, and he does seem more T-dom. He does have poor Fi; devaluing subjective manners of determining value over objective methods of measuring stuff, as if the personal is silly, is very inferior Fi. However, all P types will tend to value subjective reasoning methods as long as they are consistent in themselves, whether Ti or Fi. Contrary to popular belief, Ti is not "objective", but it's subjective in that the subject assigns validity to their individual premise without immediate need of fact to support it.
I don't see Ti or nearly enough Se for him to be ISTP. He doesn't show any motivation for understanding fundamental systems or creating his own systems, but rather aligning his own actions logical cause and effect so as to achieve a goal. That's Te - figure out how to go from A to B to get a result, but the desire behind a goal is the weakness (if it has Fi reasoning, then it gets dismissed as useless, but of course it sneaks in unconsciously). The main wedge between him and the female lead is that he doesn't want to validate his own feelings/needs, whereas IxTPs don't want to validate the common social methods of establishing values and meeting needs. The latter is seen more in Te-dom.
I think his enneagram is 3w4, which is why he appears ambiguous in terms of I/E, but that e-type is also better suited to eNTJ.
I know more about MBTI/Jungian theory than this show*, but from all I saw, he seemed introverted (locking himself into a room for days to work, if I recall), very private about his ideas (NPs are more willing to share the process), but not private about his feelings (expressive, opinionated, like it's obvious and not "personal", but still a human-oriented outlook = Fe aux). He seemed pretty rigid and to have singular visions, which points more to Ni than Ne too. He didn't seem knowledge or mastery driven, but driven to express and explore human experience in an abstract way (NF over NT). Also an obvious enneagram 4, which makes NT unlikely.
* [MENTION=22067]riva[/MENTION] 's rep, I hardly watch TV & never made a point to watch this show, but my mom regularly watched the edited re-runs of this while making dinner, and I'd be hanging out in the common area of the house (where the computer was located

), so I'd see it in the background. That's essentially how I acquire like 90% of my knowledge of mainstream pop culture, recent news, and everything else outside my rock.