I was already a Metal fan before getting into Opeth, but I had, prior to them, never listened to growl vocals. Now, they don't bother me at all, and in the case of certain bands, like Opeth, they're quite amazing.
Anyway, I agree, get 'Still Life' first, but Orchid is pretty amazing as well.
If mediafire wasn't rejecting my uploads, I'd share 'Lamentations' as well, because its a great album. Lamentations is live, so it has some variation throughout their library, including the 'Damnation' record, which is all acoustic, no growls, like, for instance, "Benighted" from Still life.
Anyway, I'll try uploading it again. Lets hope it works...