Please help a Marine pick out a Scotch for his Dad

So I am hoping some of you Scotch connoisseurs can help me. I recently found out my girlfriend is pregnant which I am stoke about and my Dad will be extremely excited as I'm 29 now and it will be his first grand baby. My dad loves Scotch but he is a middle class, average joe and wouldn't spend more then 25 dollars on a bottle for himself. He drinks Dewar's White label on the rocks, which he really loves, but I would like to buy something a lot nicer to give him when I share the good news with him while I'm home on leave. I'd like to have a drink with my dad. The problem is I know nothing about Scotch. I wanted to know what a good choice might be for my dad, who likes Dewar's white label, if I wanted to by him something a lot nicer. I'm looking to spend about 125 to 150 dollars for a 750ml bottle. What do you all recommend that a Dewar's white label drinker would appreciate?