These days I mainly just follow Taguchi Junnosuke from the group, as he has always been my favorite member and I love my dorks. And it has worked out well with me having to keep a livable budget as it means not having to buy much KAT-TUN related.
If I can find the Japanese version of their albums cheap I will pick them up, as long as they have a Junno solo on them. And I will pick up an single that has a Junno solo. In fact the limited edition of Face to Face with Junno's solo, FLASH, was the last KAT-TUN CD I have purchased. I definitely have no regrets for it as Junno has improved his singing and sounds so good in it.
While I am more a Junno fan than a KAT-TUN fan I have nothing against the other members of the group. If they happen to be in a program I want to watch I have no issues with it. But they just do not stand out to me, which of course is just a personal taste kind of thing in the end.