The Second City is as good as it gets. These are solid professional comedians that know how to work a crowd.
We made reservations (which I recommend you do too) and arrived 30 minutes before the show. Already at that point the place was really full.
We saw This Party's a Riot who did a lot of modern sketches based on current events and made me laugh until my side's hurt.
The best seats in the house are in the center of the stage, balcony seats are great too (just avoid the far left or right if you can).
The service was fantastic (our drinks were kept full and we got our bill and were able to pay promptly as the show was ending).
I'm going back in a couple weeks to see the Cabaret. I'll keep you posted. I am really excited for it!
***Tip: Get there early...good seats make a BIG difference. You really need to be able to see their faces well.***