Thanks to my previous employer, in St. Louis, I attended the first two Strange Loop conferences. Although I wasn't able to go the third year (2011) I saw it's been growing by leaps and bounds. I think Strange Loop has the potential to be one of the big professional software conferences.

Strange Loop is undeniably awesome and everyone should endeavor to go sometime, but as a multi-disciplinary conference aiming for 1000 attendees this year, it's neither niche or small, unless I misunderstand the OP. A "cool conference" though, for sure.

I second Big Omaha. Third year going.