For everyone who keeps saying that waiters/waitresses/servers/bartenders should get better paying jobs, you might want to consider that the federal government and very few states actual require that restaurants/diners/etc. pay these people what most consider minimum wage. They actually have what may be considered an alternative (and considerably lower) minimum wage. Why? Because the government expects these people to earn the bulk of their money from tips! Also consider that we are recovering (rather slowly) from the greatest economic recession since the Great Depression. This means many of these people (and many people in general) are happy just to have a paying job. Finding a better paying job isn't a feasible option for some people right now. Plus there are a variety of other reasons people take waiting jobs, such as schedule flexibility. I've wanted to quit my job for years (no, I don't work for tips, nor have I ever), but right now I can't find another job that will pay me as well as where I'm at to start, much less one that will pay that much while allowing me the schedule flexibility to go to school. So I stay.
As for myself, I usually tip very well, assuming the service was good. I've actually been known to tip 2x the recommended amount or more, but when the service has been exceptionally bad I have left without tipping. The latter is extremely rare, but if I'm thirsty because I haven't had my drink refilled in 40 minutes and have to hunt you down 20 minutes after the meal is finished to get the bill even though there's a guy mopping the floor because the restaurant is now closed and then you throw me attitude for asking for the bill (this has happened, and you couldn't miss us as we were a party of at least 20), at this point don't expect a tip.
On the plus side, tipping can sometimes benefit the tipper as well. If you have a favorite bar/restaurant, the waitstaff will remember if you're a good or bad tipper and cater to you (or not) based on that. For example, a bartender at a place I go to occasionally (literally only once every 3-4 months as I don't really have money to go out right now) always remembers me. I always get fast service, and he makes my drinks stronger. Since he makes my drinks stronger, I don't buy as many, so even though I'm tipping more I'm actually spending less on my night out. It's win-win.
On a more humorous note, check out the movie Waiting. Just a warning, it's not G-rated. Don't mess with the people who handle your food.