The buildings are spread out on a large well designed green area which is reminiscent of the mall in Washington DC. Even with the huge number of visitors during the Easter break we did not feel immersed in a crowd. Independence Hall is on one end and dominates the view. The Liberty Bell is housed in a separate pavilion from the visitor center and is well worth a look.
We visited the Liberty Bell pavilion and waited for about 5 minutes to pass through security. Our nine year old niece was overheard talking to our nine year old daughter. "Can you believe all this boring stuff was built for a bell that's BROKEN?" For adults and teens however, the displays in the pavilion were thoughtful and enhanced the experience.
I wrote a separate review on Independence Hall. We enjoyed the visit, but there are just too many people in each tour and we felt rushed. We had trouble hearing the ranger and the small ones in our group were bored. If you go, try to keep near the front of your tour group so you can hear the ranger and actually see the rooms instead of the backs of the heads of the persons in front of you.