Best Lead Generation Service?

Tough call. There are like 800,000 of these fly-by-night "lead generation" services out there, and they all seem to reduce to pretty much the same thing: spam the hell out of everybody via email and LinkedIn messages. I get spammed by 5-10 of these outfits a week, and none of them impress me, especially considering that the best they can do at generating leads for themselves is generic spam.

If I just wanted to spew un-targeted / generic spam at people, I could do that myself and don't need to pay somebody for the privilege.

Maybe there's a good one out there. My guess is the only way to find out is to try a handful of them and see if one works out. That or get really lucky and have somebody (on this thread, or elsewhere) speak up and say "Oh yeah, we used $FOO and they're great. Call and say $BAR sent you." But I'll be a touch surprised if that happens, personally.