I call for knowledge skill rolls a lot, but I must admit, there are some skills that, unsurprisingly, get more use: Seattle, Knight Errant, police/security procedures, matrix security and Matrix design.
For a lot of the interest skills, either I as the GM or the players have to work to make use of them. I have to plan for knowledge of VR games to be relevant. Knowledge: Fashion has been used a few times to judge an NPC's social class. Making them useful takes doing. But I think it's worth it. One of my favourite parts of Shadowrun is the time between jobs, when characters are living their lives and being in the sixth world, and that's when their interests come up the most.
I've also allowed them to use knowledge skills related to the topic in question but with a higher threshold, or to contribute to teamwork rolls with knowledge skills. These have been good for increasing their value.
I might try giving them some bonus points for interest skills, just to see what they use them for and what I can get out of them. This is a groovy idea.