I only drink Diet Caffeine-Free Diet Coke and Diet Caffeine-Free Mountain Dew. Although, from a fountain, I always take Coke Zero over Diet Coke, because Diet Coke tastes really bad from a fountain unlike cans or bottles, but Coke Zero does not. I'm not sure why, but it's really strange.
EDIT:
I actually used to dislike diet sodas because they don't taste as good, but I changed my opinion one day when I was at a hotel and I think the vending machine had Diet Coke. I recalled a friend that pretty much only drank that, so I thought I'd give it a shot. It actually wasn't too bad and it tasted a lot like normal Coke. Combining that with the fact that I got way too much of my daily caloric intake through soda, I decided to drop all non-diet.
As for pop vs soda vs soda pop vs coke... Northerners typically call it soda. Using Coke is more of a southern thing. I do recall someone posting a map of the US that plotted out which areas used which term. You can probably find it with an image search.
EDIT 2:
http://quittingsoda.com/wp-content/uploads/2008/09/popvssodamap.gif
Here's a map.
EDIT 3:
Nevermind... someone already did

. Not hard to miss things on a phone.