I usually have the problems with the thirty year olds that think they are hot shit...
I think that about some people...except it's not a compliment...
DIGRESSING
Automatic tips in restaurants. Give me any semblance of service and you get 20%, but that's my choice. Everytime I've been in a restaurant that has automatic tips, I have gotten piss-poor service everytime while my/our waiter or waitress sits chatting with friends.
Ordering something, explaining several times that it is as an appetizer, and they bring it with the meal, saying "I put it in with the meal<" then get all pissy when you refuse the appetizer, because you intended to eat it BEFORE the meal, not WITH
Wait staff who pass by your table and even make eye contact, and come back only afer you've sat there for 20 minutes and give me that "I DIDN'T SEE YOU THERE." That's because I'm out the friggin door. Don't penalize me because your manager doesn't know how to manage sections.
If I ask for steak or tuna rare, and you give it to me dry as a bone and cooked to the consistency of leather (i.e., nothing that could be considered anything close to rare), especially fish, it's going back, I promise you. I have a friend who managed an Applebees in my old hometown and he has said there is no excuse for that.
Adult Swim after midnight. Aqua Teen Hunger Force and Robot Chicken are fine. "Tim and Eric's (watching paint dry would be more) Awesome Show" and "MetalCrapocalypse" suck big time. No wonder I watch TNT more; give me Stella and Montana (from CSI:NY) anyday over Tim & Eric. Hot female women rule.
I can explain about the diet soda with an otherwise-unhealthy dinner thing. I personally can not stand the taste of regular soda. Usually I eat pretty healthily, but once in a while I wouldn't mind some fried chicken or a 5-inch thick block of melted cheese (just kidding) and I'm not switching my soda choice accordingly. I think a lot of people probably see it, not as a balancer, but as not making things even worse, or, like me, people just can't stand regular soda.