For the most drinkable cider, simply adding yeast to the cider gives you a nice 5-7% ABV drink. You can boost the ABV, and the cider will become more wine-like. I actually make an apple wine out of apple juice/cider and it's great. It's not like cider, though- more like a fruity white wine. It's up to you- both drinks have their place. If you want a more apple-y drink, pure cider is the way to go. If you want a more wine-like drink, add some dextrose to boost the SG up to the 1.070 range (or higher- mines' around 1.095 and finished at 12%)
Just about any yeast you use will have the cider finish dry. It can be sweetened though, after fermentation is over, by either stabilizing and adding sweeteners or by adding unfermentables sweeteners.