When I first entered the Kimmel Center, I just couldn't believe that I was in Philadelphia. It was just so tasteful, so awe-inspiring, so well designed and visually pleasing that I was very excited to be here. The lobby with its atrium, the glass roof... Ah... Perelman Hall with its lights and wood floors and plush upholstered chairs, the ushers taking you to your seat. Wow! This place is brand new (almost)!
If you like the orchestra, Verizon Hall hosts many concerts. (most of which are pricey) You can even become a patron of the arts when you donate to become a "member' of the center.
You can also watch plays here, but they are nothing close to what you'd see on Broadway. Except for the fact that they are way cheaper.
I happen to know that you can get tickets for $10 if you come right before the shows start in the evening. That's a really good deal.
I've heard that the gift shop and the restaurant are overpriced, but I've never visited them.