When you go to drivewire.com, and enter your car info, up pops spark plugs and prices. For my 98 GS-R, it shows NGKs at about $12 each, Densos at about $6 each, and Bosch Platinums for about $3 each. (There are also Bosch at $1.50 each, but I assume they are not platinum.)

My owner's manual lists NGK and Denso; I went with Denso.

Would Bosch Platinums work? I'd guess probably yes; how complicated could a spark plug be, after all. But I don't want to worry about saving $14 for items that are replaced every 60k miles.

If my owner's manual hadn't listed Denso, I would have gone with NGK.