Which spark plugs are the best for Mazda MPV 2004 model?

I really like NGK, but in the right applications. I prefer them in high compression, low displacement engines, and in dirt bikes. That's just a personal preference, and really isn't based on science. If you go to the parts counter and say OEM replacement, and don't buy the cheapest one on the list, that generally should do fine. What makes it seem they don't work well?

It's quite possible there is another issue causing your concerns .. I have used NGK brand spark plugs & other products on customers vehicles as well as my own for several years with nary a complaint!