I just read somewhere that coke is coming out with a Diet Coke with splenda. They aren't getting rid of the regular kind, they're just adding a splenda version too. I'm not sure when it will be out though. I agree with Susan that Diet Rite is pretty good and it does have splenda. I think there's another kind that has splenda too but I can't remember right now.
I'm drinking diet V8 Spash right now. It uses Splenda. I turned my nose up at it when I read the ingredients, consiting of carrot juice. However, it tastes more like an orange drink. I can't taste any carrots, or any vegetable at all. It's a fruity flavor. They have a new one that is berries and also has carrot juice, but I keep hedging on getting it because I'm afraid to try new things. LOL
If you can get it Hansen's "Natural" Soda (DIET) uses Splenda. I love this stuff but not sure if you can get it outside of North CA. I especially love the tangerine, strawberry/kiwi and the Root Beer is amazing! The Ginger Ale is nasty though, I'd steer clear.