Morrison's stuff is pretty good, especially the first year and a half. Afterwards it gets a bit repetitive in places. Rock of Ages is my favorite of his run and DC: One Million is pretty good as well. Earth 2 is worth checking out also.
Can't really recommend anyone who's followed him on the series.
As well, I recommend the Giffen/DeMatties Maguire JLI stuff. Very different from the standard JLA stuff, but very good and hilarious.
