Use really good cocoa, too -- I like Cacao Barry ($20 for a kg on amazon). It also makes fantastic brownies. (People think I am some kind of baking genius but really, it's that they're used to Hershey's cocoa...)
Pick up Lebovitz's book The Perfect Scoop -- it has a whole section on stuff you can add to ice creams.
The ingredients in that recipe are a touch weird (who measures in cans? and you should only use the yolks, not the whole egg), but the method is extra strange. Here's how I make ice cream:
Check out The Perfect Scoop by David Lebowitz for more general ice cream making tips.
Adapting them to sugar free is relatively easy. I haven't used Splenda in ice cream, but I've used it 1:1 in lots of other things and it works great.
Keep trying cause once you figure it out, you won't want to stop. =)
If you can't be bothered with cooking together and chilling a custard base, the Ben & Jerry's recipe produces similar results with much less fuss. I actually prefer it since it lacks the distinct flavor of scalded milk. I'm also lazy.
Whatever recipe you follow, you can always scoop the ice cream right out of the bowl, but for a more solid texture freeze in a shallow container for a few hours. In this case, adding an emulsifier such as arrowroot or xanthan gum helps but is by no means necessary.
If you eventually want to buy a book, The Perfect Scoop is very good.
Do you like ice cream?
I bought a Donvier ice cream maker a couple months ago, along with a copy of The Perfect Scoop by David Lebovitz. I've also gained about 10 pounds.
A few other books that I love and continually use are The Accidental Foodie, The Southern Italian Table, and Mastering the Art of French Cooking. If you're looking for an accessible book on french cooking, I definitely, definitely recommend that last one.
Ice cream made from beer is very good, too. I made Guinness Milk Chocolate Ice Cream from David Lebovitz's Perfect Scoop (Using Sam Adam's cream stout instead of Guinness). The light hoppiness of the beer really complimented the chocolate. Apparently Emeril makes a good Guinness ice cream, too, but I haven't made it.