Hawkman improved a bit once Leifeld came on board (and yes, I'm surprised by that sentence too). The recent multi-part crossover with Green Arrow and Deathstroke, however, has blunted the improvement somewhat (by tying the book to two other titles that aren't quite as enjoyable, imo).

I've also found Justice League to be quite better when I read a complete arc, rather than the singles. There are more subtle moments to the story than some people have realized, I think.

Superman has improved quite a bit under Lobdell.

I don't know; I'm really enjoying most of the books I'm reading. These were the ones that I sometimes found myself a little disappointed with initially.