In June 2000, my wife and I met all of the dwarves outside the gates to the MK before EE. They were out greeting guests and having a grand time, and yes, Grumpy is awesome. (Bashful is also a fun character)
Daisy Duck we met last summer next to the Photo Emporium place when you first enter the MK on the right. This was about noontime, so watch there for characters.
We also got a chance to see Jasmine and Aladdin together in the Morocco pavilion.
However, my two favorite meet & greets were with Mickey and Minnie together in front of the castle VERY early last June. It was our first day at the parks and we were probably the first hundred or so people in the gate. Just as we reached the hub, Mickey and Minnie walked out of the castle and posed for pictures/autographs. It was my DS and DD (then 6 and 3.5) first autograph!!! The second favorite was probably Sorceror Mickey at MGM...tucked away in a little building near the commissary.
Almost forgot, we met Kermit & Miss Piggy together in their hollywood clothes outside the Muppet theater.
Who I'd like to see......
Darkwing Duck
Mike Wazkowski
Darth Vader (we'll be there for Star Wars weekends this June...maybe then)
Chewbacca
maybe Nemo????? His movie starts the day before we arrive this year.