Easy. The absolute most ideal INTP trait -- that which is so entirely invaluable that it cannot be dispensed with, without entirely destroying the value of the INTP experience altogether -- is the ability to make very precise, fine, and clear distinctions between even the most complex and abstract information -- an ability which I call, "conceptual acuity." Without this computer-like ability to break down and sift through tough, abstract information, we'd be like almost everyone else.
Also, it has to be mentioned that our (extraverted-intuition-driven) inclination to seek "unusual," or "unobvious" (and perhaps somewhat "creative" or "unconventional") solutions to an entire array of problems, really is a very valuable aspect of the INTP mind/personality, as well. As coupled with our conceptual acuity, this compulsion often leads to rather inventive conclusions based on some very sharp/deep analysis. Yet, in comparison to our conceptual acuity (or even the general Ti ability to draw fine distinctions at all), I wouldn't say it's this Ne ability which really makes life as an INTP so unique and exciting.
Moreover, while much of this sounds generally like "Ti dominant" characteristics, there is a distinction to make. INTPs are likely "conceptually acute," whereas ISTPs are more "mechanically acute." Thus, while ISTPs may have similar cognitive powers, they are more driven to draw fine distinctions between various types of complex concrete data (such as mechanical systems), whereas INTPs are driven to make sense of highly conceptual, highly abstract information (such as philosophical systems).
At the end of the day, however, I think the general Ti inclination to draw fine distinctions from any sort of information is what I truly enjoy about being an INTP (with our Ne traits coming as mere "additionals" or unessential "supplements"). [The "thinking" is essential -- not the creativity.] And thus, the question isn't really, "What do you enjoy about being an INTP?" and instead, "What do you enjoy about being a Ti dominant?" Because it's really the introverted thinking -- in general -- that I love most about this type of personality.
Or maybe, my answer to the original question is this:
I enjoy Ti dominance the most as an INTP.