You should choose a space for your event according to the kind of event it is, and make sure that it's large enough to comfortably accommodate all of your guests. Find out what's in the space - does it come with furniture or equipment?
A conference is a place for professional communication. But professional doesn't have to mean boring. Put on a conference with a funky theme. Choose a venue with a creative interior for a conference that's not only interesting but also fun!