To be honest shredders like Paul Gilbert and Yngwie Malmsteen don't influence me much (no offense to the many fans here). Rather, I get influenced by those I see to really stand out in terms of the music they write, their playing style, etc. Versatility is also something I see in those I am influenced by.
I can't say Tony Iommi was a big influence on my playing because for most of the time I've been playing, I've been into either the blues, or really intense stuff like death metal. Recently, though, he's become a minor influence for me because I'm not into speed anymore. Sabbath's riffs are the perfect stoner riffs. Slow and heavy. Pity though, I can't play Sabbath stuff because I'm not a big fan of downtuning. But he has influenced the way I play metal to quite a big extent recently.
So yeah, thanks for reminding me! I'll name him as an influence for me too.