Death Note is the more mainstream work, that's easy to say, but I find it much less interesting as a media production. In a few words...I have very little to comment on about Light Yagami as a character at this point. I've grown increasingly tired of him after each viewing. There's a lot more you can talk about with Lelouch, whether you like or dislike him, and that's a big part of why I'd rather rewatch Code Geass myself. I've already done it a few times.
Furthermore, Code Geass also has a certain jack-of-all-trades charm and I happen to like that. I also enjoy researching and reading up on the behind-the-scenes materials, which have added another layer of appreciation from my point of view.
Content-wise...it's got issues, yeah, but there's absolutely a method to the madness and not pure randomness for its own sake. Even in R2, which is clearly the weaker half. Frankly, the ending manages to pull together quite a few threads in a surprisingly effective manner if you can accept its internal logic.
I watched Code Geass after it wrapped up and enjoyed it quite a bit. I didn't get the whole "so stupid and wacky" thing people talked about, at least I didn't think it was significantly more off the wall and incoherent than the average action/adventure anime, even if it was obviously convoluted and nonsensical at times. That said it's been over a decade since I watched it so it's very possible my tastes would have changed but I would call myself a fan.
To be fair, I do think the show is quite intentionally over-the-top and exaggerated because of the stylistic, melodramatic approach chosen by the creators, but still...yes, I find it odd how some viewers have a low tolerance for crazy plot twists when they happen in Code Geass, but can accept them elsewhere. At the same time, it's not like the series is predominantly hated or overwhelmingly disliked, no matter what certain folks may think. It's still relatively popular and gets new fans all the time.
