For me it's the Ozzy years all the way. But then I'm from near B'ham and he's a local hero (along with the rest of Sabbath, Plant & Bonham).
That run of the first six albums is just unbelievable. Hard to pick a favourite, but I think it may be "Master Of Reality".
On a slightly different topic; I think my favourite Sabbath-influenced bands have got to be Soundgarden and then the whole Palm Desert scene - Kyuss, Queens Of The Stone Age etc. Is it me or is Josh Homme (and his crew) the only current artist worth listening to? I know that's not strictly true, but it sometimes seems that way.