I heart The Shelf. Hard.
It pops up a few times a year for three week seasons and I have never failed to have a great time.
Brainchild of Justin Hamilton and Adam Richard, the guests are many and varied, so it's hard to accurately review this show. I can tell you though that I've been to several seasons now, and I can only think of a couple of acts that I didn't like. Each act is only on for a maximum of about 10 minutes. This is both good and bad, if you don't like them, they will soon be gone. If you do like them, they will soon be gone. But I have gone to see entire shows from people I have seen here, so it tends to give you a good idea if you will like them or not.
Because it's been going on for so long, there are a lot of 'in-jokes' that happen (something that became obvious to me last season when I took some new people along for the night and they looked a bit confused at times) but they are brief, and the rest of it is usually just damn good comedy.