Your best bet is to check the website to see who is performing the night you plan on going, then Google & YouTube them to see if you'd like them.
Comedy can be hit and miss, it's clubs like this where these guys refine their talents. Generally comedy shows are a good time, however living on the East Coast there aren't many comedy clubs (a Yuk-Yuks opened in Halifax after I moved
) so the comedians I see generally have been around the block and have been touring for a while.
Worst Case Ontario, check with the fine folks on here to see if they know who is performing, or if they were at one of the recent shows.