All the time! If the lines are short and/or I love the character, I always wait. Picture this: three single adults between the ages of 26-31 (male and females) waiting for characters.
It's also fun to watch the kids ahead of us meet and greet.
Last year I was so excited to see Rafiki (I loved the Lion King as a kid) 'he' started dancing with me since 'he' knew how happy I was to stumble across him in Epcot.
Also, someone mentioned autographs earlier. Here is what I did for some autographs that someone may be interested in.
I had Mary Poppins and Alice & the Mad Hatter sign two books that I purchased in Epcot. I knew we would be dining at the Supercalifragilistic buffet later in our trip, and I brought the books with me. I am SO happy that I asked them to sign them--they did such a nice job personalizing the message. By the way, The Mad Hatter's signature is THE BEST!! He told me that he rarely signs the "Happy Un-Birthday" message because it is difficult, but since I went out of my way to bring the "All Things Alice" book, that it needed a special dedication. So, if you're into Mary and Alice and the Mad Hatter, you may want to think of this option (or heck, any other character). It's nice to see every time I open the books, plus the neat messages will always be there. Oh, and the Mary Poppins book I had her sign is "Mary Poppins from A to Z". I'm sure that you can purchase any of these books prior to arrival to WDW. I thought of the idea while in Epcot touring the countries...so, whatever works for you!
I would do have to say that the Supercalifragilistic buffet seems to be a bit slower, so the characters had more time to sit and chit-chat. In fact, the Mad Hatter sat with us for a LONG time. It's a great buffet without feeling as though the characters are flying by your table.