I usually tip 20% or slightly more since I always leave whole dollar amounts. I've never differentiated between lunch and dinner, where does that supposed distinction come from? And 25%? Why does the amount of "standard" tip always keep creeping up? I remember when it was common knowledge to be 15%, then more like 20%, and now 25%? The price of the food is a reflection of the variable value of the dollar, so why can't the percentage remain static?
Here's one that chaps my ass: pizza delivery that adds a delivery fee, but then claims the delivery fee does not go to the driver. Now it wouldn't surprise me if that is true and that the driver gets none of it, but then why are they trying to pawn it off on the customer as a special delivery surcharge? What is it about a delivery that would require a surcharge if not the driver and his vehicle? I usually tip pizza delivery guys anywhere from 3-5 dollars, but it does irk me that the bill has already tacked on $2 with a disclaimer that the driver gets none of it.
Another question on tip etiquette, what do you do for takeout when you pick it up yourself? I am far less inclined to tip on something that involved no table service or delivery, but I still feel like a cheapskate if I don't throw in a buck.