The Sprouts Children's Theater within Second Story Repertory in Redmond Town Center is fantastic.
Their four show seasons are filled with great classics like "The Frog Prince," "Snow White and the Seven Dwarfs," and "The Brave Little Tailor." Each 45-60 minute show includes music and singing and audience participation/interaction.
The theater is intimate, and seating for kids, should they want it, is right on the floor in front of the stage. (My own daughter prefers to sit in a seat with us.)
My biggest rave about Sprouts is the $8.50 ticket price. Absolutely a great value, and if you become a subscriber, you receive a discount. Subscribers are also granted earlier access to the theater for better seating.
If you have kids and are looking for a fun way to spend some time with them (especially in the winter months), give the Sprouts productions a try!