Other apple varieties for a Granny Smith fan When I buy apples I tend to buy the Granny Smith variety. I've heard that it's more of a baking variety than one for eating directly, but I like it better than others I've tried. The only two names I can recall are  Red Jacket and Red Delicious. I know there are tons of types of apple that I'll never eat unless I make an effort. Which types should I, as a Granny Smith fan, go out of my way to try? As far as I can tell I like both the acidity and the crispness of the Granny Smiths.

Wikipedia tells me that Granny Smiths "The tree is thought to be a hybrid of Malus sylvestris, the European Wild Apple, with the domestic apple M. domestica as the polleniser." I've been unable to find European Wild Apples nor any other varietals that are derived from them.
Granny Smith's popularity as a baking variety is mostly due to its firmness and tartness, which will offset the caramalized sugars from baking the apple and prevents the apple from falling apart, but theres no reason you can't eat it plain as well. Actually I also prefer fresh apples which arent too sweet, and granny smith's are one of my favorites to snack on as well.

Now, there are hundreds of different apple cultivars (or varieties), and many will probably not be available locally, and you haven't mentioned what it is you like about granny smith apples, so I can't specifically reccomend that many apples.

That being said, I would cross reference wikipedia's list of apple cultivars with attributes you like in an apple, and see what comes up. For example if you like tart apples you could try Honeycrisp or Pippins. If you like firm apples try Golden Delicious, or Golden Gala.