Ah, Larry David eases the pain.
To address a point, though, I love to tip, and I love to tip well. When I can be overly generous, I am. When I can't, I still try to leave a respectable tip, because I like the service. The trap is when one puts too much into the amount. It's like when you have to fill out one of those self evaluation forms at work. You're likely to rate yourself higher, than what those around you might rate your performance. It's just the way we are. We want to believe we're doing a great job that is deserving of a great tip. The problem, as mentioned earlier, is what constitutes "great", "fair", and "poor". I don't like percentages because they take nothing but food cost into account, which is not a reliable method of figuring gratuity.
Put it this way: for me, aside from my basic rule of $5 and $1, gratuity is a spur of the moment thing. I've left huge tips for small meals. Keep in mind that my $5 rule applies all of the time, so even if I'm eating alone, and my meal is $8, I'm still leaving a $5 tip as long as the service was good, and it's pretty hard to fuck up a single person dinner order, especially if that person tries to offload some of the burden on the server (which I do).
Also, as Larry does in the video above, if there is an automatic gratuity, that's it. I don't give anything on top of that.