Here's the deal: My step dad has been always looking at acoustics for a while now. But he has never been even remotely close to buying one.

He has been looking at old Martin and Taylors. Anything acoustic or acoustic electric is appealing to him. We have looked at Taylor 914ce and 814 ce before. We might even consider getting a used or older guitar (because they can be cheaper and just as nice).

My question is, what are some other guitars I can show him interest in, and
how should I try and get him closer to buying one without nagging him. I need good acoustic to play too. The acoustic I play now is a piece of crap.

Any help would be great.
top axes:
Taylor GS8
Fender American Strat (w/DiMarzio pickups)
Epiphone Les Paul
well it sounds like you are in a really great position! the 800 and 900 series guitars by taylor are really nice guitars... especially if you like a really bright sound with sustain that goes on forever. you mentioned that you were considering picking up a used 800 or 900 series. i myself wouldn't do that. the 800 and 900 series guitars have so many options that you can pick and choose to your liking. if you are going to spend that much money and get such a nice guitar... get a new one so you can have it built and set up the way YOU want it. if you are extremely interested in buying a used guitar i would reccomend looking at martins. depending on how old of a guitar you want to get, you can get some really nice deals on vintage martin acoustics. on the other hand, if you are looking at golden era martins, they are going to be more expensive than a brand new guitar. this is something that you could use as a selling point with your dad. with martin especially, vintage guitars appreciate in value rather than depreciating. gibson acoustics are also known for appreciating in value, but i personally am not a huge fan of gibson. other guitars i would have a look at include the custom series from breedlove; the martin D-28, HD-28, D-35, and HD-35; the larrivee rosewood artist series, rosewood traditional series, and the rosewood deluxe series.
If you live in Canada check out Garrison guitars. They are really awewsome guitars, and good for the price. I'm in love with mine. Alveraz is another good brand, and its usually decently priced.
i'd stay away from fender's acoustics, i myself don't like them.