The C major fugue has a very fun contrapuntal style and is probably my favorite fugue. My second favorite is the e minor fugue because of all the interesting chromaticism and counterpoint.
I like the way you think! Yeah, although it would take me an envelope full of money to play the WTCI C major prélude again, even just in private, I still enjoy the fugue. For me, the WTCI C major fugue is a tightly knitted ball of yarn: there are only so many ways to repeat yet again the subject in stretto, but each time is another step toward a better interpretation.
The fugue from WTCI C maj is, as well, a tiny bit of a workout for both hands, when played at tempo and with the correct phrasing. Neither particularly long in length nor distant in modulation.
Maybe the Contrapunctus I from
Ars fuga is comparable: although there are stretti in the latter, it's difficult to find a compelling way to play it. The only solution I've found for the WTCI C major fugue is to play it rather quickly, and vary the articulation, but I don't find my way of performing it terribly satisfactory. As a Frenchperson might say, it's correct but it's not just.
Equally the E minor WTCI fugue: no, it's not maybe the most sophisticated, but I like it for the sheer audacity and the sheer fun of the chromatic subject.
It's one of those where one can try to play at absolute maximum speed, and usually it turns out all right! And the "accompanying" prélude is fun as well, if not representative of the best Bach has to offer in that key. Additionally, it's right next to the E major WTCI, where similarly the prélude is not much compared to the fugue: the E major WTCI fugue is considered one of the more straightforward fugues among "The 48," but there I have a challenging time playing it at the fairly brisk pace I think it requires. But, unlike the E minor WTCI fugue, it needn't be played frightfully quickly to be of interest musically.
However, I am very very far from being an expert on the WTC, (I haven't started even playing book 2
). so take my opinions with a grain of salt.
No, me neither, and I as well don't present myself as an expert: I wouldn't sell yourself short on the WTCII. These are not necessarily more difficult. In many cases, the opposite.
Perhaps less familiar to the average civilian

but that doesn't mean anything.
My favorite pianists that play the WTC are:
- Schiff
- Richter
- Baremboim
- Gould if I'm feeling really crazy
Edited to reply: Yeah, I'm a Schiff man myself. Gould as well (you know, with some cautions!). Hewitt.
More or less I listen to various performers to get metronome indications and an idea of the pulse (in the technical sense) for very slow "movements" among the suites. which latter are challenging for me to read off the page despite a slow tempo.
And, yes, I often use a metronome at the desk while listening to such pieces and make a note of the range of tempi.
But I like even Richter, although he's by far the most outrageous of the Bach performers IMHO. (Well, "like" is a strong word, but I do listen to Sv.R. when trying to find my way in a given piece or suite....he's the most idiosyncratic performer I can think of when it comes to Bach).
I think if forced to listen to somebody other than me play Bach, I find Schiff the least offensive. In that I hear a lot of interpretive space in his silences, so as a listener, I can imagine how I would execute a given passage during the performance.