Oh my god I loved this episode! Solid laughs and some sad truths in equal measure. I've always liked Krusty - what a great character he is - one of my favorite Simpsons eps is the Jazz Singer parody where Jackie Mason played Krusty's disapproving kantor father - and he was hilariously neurotic in this one. As for Lisa succumbing to the addiction of making people laugh...you have to ask yourself: why else would anyone try to make a living doing comedy? Damn tough business, not for the faint of heart. It's gotta be an addiction. And I loved this exchange:
Krusty (to Lisa) Kid, you're the best thing to happen to this business since...
Lisa: Mitzi Gaynor?
Krusty: Well, I was going to say "cheap Korean animation", but that'll do.
(BTW, I actually know who Mitzi Gaynor is. Long story).
And the subplot about Bart and Homer's new coin-collecting hobby was clever too. "Kissing Lincoln" LOL. All in all this was classic Simpsons IMO. 10/10.