EDIT: Spoilers for Decade episodes 2-3 in the comments, though I imagine if you click on the cut, most likely you have already watched past that.
(Found over at TV-Nihon forum)
Nope, nope, nope. It might be because I adore the character, but I'm usually not so lost. If he has such traits that make him a Gary Stu, fine, I would accept that, and probably would have liked him anyway.
Popular opinions seem to be Tsukasa isn't perfect, which I agree. He needs Yuusuke and/or Natsumi to keep him in check. Personally, I'm not too sure about that. I like to pretend he's just indulging them (man, I contradict myself*); I must admit I might be a bit irrational, after all, in my liking.
*Or perhaps not. When someone doesn't need help but pretends otherwise, that is deceit to me (therefore he's not perfect). Though it (the act of indulging) can also be seen as a form of tough-love kindness I like to attribute to Tsukasa.
In any case, he is the main character. Whether I like it or not (I do), the series is going to spend a lot of time on him. The show is called Kamen Rider Decade, after all.
At a time like this, I'm so glad I'm a main character fan. I would rather see plenty of the character I like in a show where I know he will get plenty of attention, rather than be a secondary (or other less focused) character fan and have to wait for a story (or a whim of the writer(s)) to get some focus of the character I like. (Well, maybe the rarer appearances might make the experience (the wait) all the better, I don't know. I still would rather go with a sure thing, though.)