If the Aerons weren't that comfortable, but you're still ok with spending a bit more for quality, I've been pretty happy with my ErgoCentric for the last week or so. There's a couple more brands out there, check locally for "ergo" focused places, more so than "furniture" stores, and go from there.
If budget is more of a constraint, you should be able to find something there, but durability won't be the same. And whatever you do, stay away from non-breathing faux-leather.