I've been chasing a misfire problem on my daughter's 2000 Accord Ex for a couple weeks now. 150k miles. Plugs and all maintenance done 5yrs ago when we bought it. Misfiring very badly under load below 3,000rpms. Idled fairly well, but not perectly. Above 3k RPMs, no issues at all. Replaced the distributor cap and rotor due to arcing & corrosion. No luck. Replaced the coil. No luck. The plugs only have 30k miles on them over the last 5yrs, but that's the next cheapest step ;-). Might as well...
Except... The friggin' plug boots are frozen to the plugs! Took me 5hrs to chisel out the plastic boots from around the plugs before I could remove the plugs.
Long story short, new plugs and wires have solved the problem. I had to yank the valve cover gasket working on the boots, so I adjusted the valves while I was at it.
Car idles so smoothly now that is hard to tell it's running! The symptoms sure pointed towards VTech-related issues, but the simplest fix did the job. Seems stuck/melted plug boots are a common problem as well. Doh!

 

Use the factory wires from the dealer(sumitomo/prestolite) or NGK from the aftermarket. Most brands make the spark plug boots incorrect, they either do not fit or disintegrate.