diznefreak,
Of course you'll get various opinions on this one. Here's mine. We never miss PI. After experiencing it a couple times, we no longer go to anything but the AC and the CW. Background: I'm 40, my wife is 38, and have no children, although June will be the last trip we can say that (I stick that in anywhere I can). We aren't lampshade-dancers, but we like a couple of drinks. As for doing PI after a day in the parks (more important, between two long days at the parks), be warned: You'll have a good time and might not be able to leave until closing. But it's doable. Obviously depends on your stamina. Just count on the day after being one of those days where you aren't dashing to rides.
Why only AC and CW? The CW is something we don't have up here in Central PA, so we like to see a show or two. It's good improv comedy. If we had such a club locally (we had them when we lived in Philly), I'd go to nothing but the AC.
If you're into dancing and nightlife, I guess the rest of the clubs are for you. The Jazz Club has really good jazz. But I can get that here. 8 Trax has a neat theme, but fifteen minutes after you're there, you get used to your surroundings and it's just a bar. I feel the same way about most of the clubs at PI. They're really, really nice clubs. But I can go to a club here when winter has me down.
However, the AC, in my opinion, is the only "Disney" club there is. With characters, things on the wall that talk, shows, interaction, and excellent theming, I find myself forgetting where I am or what I was doing before I came in. I've been in there where the atmosphere makes me not trust that the person sitting next to me isn't "part of the show." The library shows (considered the "main" shows) are excellent, but for a most excellent evening, sit in the main lobby and just observe. It's "magic."
A warning: If you sit upstairs thinking something will happen up there, not only won't anything happen, but the characters on the main level will begin to make sport of you.
Pat