I would try to spray some stater fluid in the intake by removing the rubber boot infrom of the MAF, while holding the throttle wide open, and have some one else give it a crank. Starter fluid evaparates really fast so if you spray some in, than run inside the car and step on the gas and crank it it may be gone.
If you say the spark is good and a spare plug shows a crisp spark my guess would be no fuel, as in the fuel pump going bad. Do you hear the pump run for a few seconds when you turn the key to on? (before starting)
Take out a plug and see if its soaked with gas,, if you have a fuel pressurer guage you can tap into the fuel rail and test the cranking pressure.
