i'm not really a scotch drinker, but when i do, johnny walker black is my favorite. mid priced, but still has good character. single malts are a bit much for me, but most people who are scotch drinkers enjoy the nuances of those.
I went to a johnny walker tasting thing and I did like the black, but not more than the green..yum. I think gliffinditch (sp?) arberlour (sp?) and glenlivet (oh wow I am not sure how to spell any of these names) are single malts I've tried and liked. Yummy aftertaste...I don't drink scotch though, just when offered.