[JC]

I still think if the engine cranks over OK, it has to be the igniting of the fuel that is the issue. Only 6 major things in play for that:
1. Fuel filter blocking supply (Filter changed, so not that)
2. Fuel pump - needs to pump at the right pressure or fuel just won't get to where it needs to go
3. Injectors - they deliver the fuel to the cylinders. But it appears they have been cleaned recently, so probably not them.
4. Coil Pack - not enough power to generate a spark
5. Leads - not carrying spark to plugs well enough (doubtfull though, as usually one or 2 leads go at once, not the whole set)
6. SparkPlugs - these could have worn tips or something preventing the spark from arcing properly.

If even only one spark plug is getting spark, and that cylinder is getting fuel, the car should just about start - it may not run well, but it would start. So...I'd pull a sparkplug out (and stuff the sparkplug and attached lead into a glove or wrap in a rag so it doesn't arc somehwere and possibly cause a fire), and turn the engine over for say 5 seconds. Then check to see if fuel has been injected into that cylinder - if it has (you should be able to smell it, or perhaps feel it by putting your finger in the hole), then it's a definite spark problem. I would be strongly leaning towards the coil pack, but only after thoroughly checking all spark plugs to make sure they are all clean, and not worn out etc, and also checking every lead.

For the sake of $100, It's probably worth chucking in a new seat of plugs and leads for a start anyway, just to eliminate that as an issue.

I'd put $5 on it being coil pack though (assuming fuel is getting to the cylinders).