People must really perceive tastes differently.
For me Coke Zero tastes almost like Coke Classic. The new Pibb Zero is fantastic too. Those and Pepsi One are almost all I drink anymore.
The new Frescas are very good too if you like citrusy sodas.
I like Splenda drinks but to me Diet Coke with Splenda tastes horrible. I’m not picky and will drink almost anything (diet) I can get, but I go out of my way to avoid that one.
I like Coke Zero. To me it’s almost exactly like Coke Classic with a vague citrus taste, and I like Coke Classic.
I usually drink Diet Pepsi, however. It’s cheaper.
I think Coke Zero tastes like mule sweat.
Love it or hate it…it must another genetic tasting difference. You know, like some people can taste an extremely bitter substance in broccoli and some people find taste something soapy in cilantro, and in both cases the majority people go, What are you talking about?
Me, I find Coke Zero horrible, but both broccoli and cilantro are fine.
I’m a “cilantro is soapy” person.
Update: I bought a 12-pack of this Friday because I needed soda for work and none of my usual top three preferences was available, and drank a few cans, whining and bitching with each sip. I replaced it with good soda (Diet Dr Pepper! Quaff of the gods!) this morning, and left the remainder of the 12-pack (about 8 cans) on the counter of the office kitchen, marked “free soda.” All but one can is gone (approx. two hours later) – now I’m wondering if I shouldn’t have disguised my handwriting better in case disgruntled coworkers come after me.
OTOH, this crew is known as “the bottom-feeders” for their willingness to finish off any type of leftovers imaginable…
twickster, you’re a freak. 
Your dislike of the greatest diet soda known to man is enough in itself, but to actually like Diet Dr. Pepper? Dude!
–Cliffy
I prefer Diet Coke, but I don’t mind Coke Zero.
I fear they are planning to switch formulas. If they do, I’ll whine for a couple of weeks and then be fine.
Coke Zero tastes like Tab. C2 tastes like watered down Coke which tastes like ass.
Man, I need to expand my taste horizons. I haven’t ever tasted mule sweat OR ass. I feel so provincial.
My husband MUST have a case of Coke Zero each week. I don’t know HOW he drinks the stuff! I prefer Classic Coke, myself, but I don’t drink it very often, as I don’t care much for soda. Every now and then I will get a craving for it, though, and I will open a can, but rarely finish it. I drink water or unsweetened, brewed iced tea most of the time.
Splenda tastes like a scouring pad.
I love Coke Zero. I used to be a die-hard Diet Coke drinker, but I’ll pass up DC for C0 every time, now. I like the vaguely citrusy undertones and the less strong aftertaste.
My pecking order:
Coke Zero
Diet Coke with Lime
Diet Coke
Diet Coke sweetened with Splenda
Diet Coke with Lemon (if still made)
Diet Pepsi if there isn’t any Coke products available.
I recently had to switch to diet sodas. They all tasted like crap at first, that aftertaste is nasty!
But after a while, they kind of grow on you. I can’t drink any of them warm, though.
I like (in order of preference):
Diet Dr Pepper
Diet V8 Splash
Coke Zero
Diet Coke
Diet Coke with Splenda
The last three I’ll mix with bourbon, but I really don’t like the one with Splenda much at all.