1999 Chevy Tahoe Vehicle Won't Start

I have a 1999 Chevy Tahoe. For the last two years I have had a problem with it starting. I have done several things to it and each time I manage to get it to run for about 3 to 6 months until the problem reoccurs.

It has 62 psi fuel pressure when the key is turned on then off. The fuel pressure at idle was within spec after I replaced the fuel pump this fall. The spark plugs also have fuel in them. Three of the plugs were so wet that I could shake fluid and carbon out of them.

The engine turns over, but it does not sound like it sparks or fires. I have replaced the spark plugs (15,000 miles ago). I have replaced the plug wires (just now). I have replaced the fuel pump (twice however last was 5,000 miles ago). I have replaced the fuel filter twice. I have replaced the air intake temp sensor, coolant temp sensor, and Crankshaft Position Sensor. I have cleaned the Mass airflow sensor. I replaced the distributor cap and rotor about 20,000 miles ago. Fuel Vapor Sensor 30,000 miles ago.

Two weeks ago it started idling rough and had extremely rough acceleration. The check engine light came on. I read the code and it was a P0300 code (Random Misfire). The vehicle continued to run fine with out issues after I filled up with new gas (this may have nothing to do with it).

I have tried a lot of different things, but can't seem to find the correct answer to this problem. Is there any suggestions on what I have not looked at yet?

Thanks