Lain and Technolyze aren't shows to marathon.
Gunbuster/Diebuster = perfect marathon.
I haven't watched Bacono myself, so I can't comment on that one...
Black Lagoon generally delivers good action which gets darker in the second season. It can be marathoned, or watched in small parts.
Haven't watched Ichigo Mashimaro either....
Paranoia Agent is a good one to watch while high, if you do drugs, otherwise I can't say it lends itself to either marathoning or a slow but consistent watching.