What is your standard tip in a full service restaurant?

I'm a gen Xer and I remember being embarrassed that my dad only tipped 15% at restaurants, but I think I'm starting to understand that maybe he just didn't get the memo that 15 had become 20. Or maybe it's hard to believe that tip percentages keep going up and up. Anyway, I tipped 20% for the longest time and over the last 5-10 years I've upped that to 25% for standard, good full service at a restaurant. A friend just told me that she does 30% now! Someone please give me the memo. :)

Update! This wholly unscientific survey surprised me. We're not anywhere near 30% yet and 25 isn't even the norm either. Here's how the comments stacked up.
20% tipping is the most common, with 20 people (a whopping slice of the pie!).

• 15% to 18% tips are next, but much less frequent. (9 so far)
• 25% tips exist, but only 2 people say they leave them.
• A lonely one 10%er hanging onto the smallest slice here.