Is there any aggregate site(s) to find tech related conferences/conventions that have public attendance?

In person or online for anything tech related such as hardware, software, development, gaming, etc.

In the past I've only found conventions by chance or through work related means. Through work was always related to the services we used, which was awesome, but very limited subjects. Unfortunately don't have that option anymore.

I get super jazzed and motivated when I'm able to attend but I've really never been able to find any when I'm actively looking.

Additional question: what's the last convention or conference that you were really exited about but it turned out to be a disappointment?

For me, there was a game developer conference at a local university that turned out to be only a few hours and three guest speakers, no Q and A. It was interesting at least.