Too many! I've never understood the appeal myself, as most of them end up being grossly inferior to the source material. Comic publishers obviously like them since they can hook into an audience without having to spend much on marketing, but most of these books fade away once the nostalgia factor wears thin. I can't think of any that I'd personally buy based solely on the property alone, so it would depend solely on the creative teams behind the property in order to draw me in these days.

Oh, except for ZARDOZ, which I'd buy sight unseen...