If you want a hotter sound, you want ceramics, if you want a brighter cleaner tone, go for alnico magnets. I've heard great things about the Gibson 57 (neck) and Gibson 57 Plus (bridge) combo, and I'll be putting that in my Les Paul around Christmas. But again, I've heard great things about Burstbuckers, some of the Seymour Duncan stuff, some of the Dimarzio sets, etc.
I'm sure Jeff has tested more than I have though, so wait for him to reply! I know you asked for his opinion in the first place, but I thought I'd give mine too


Alex