Put yourself in the the interviewer's shoes. You are interviewing for a Business Intelligence analyst and are down to the final three candidates who are roughly equal in qualifications and skills. Candidate 1 speaks passionately on surfing. Candidate two speaks passionately about Web Design (which is technical but not what this position does) and candidate three speaks passionately and knowledgeably about Informatica (which is a tool your company uses). Which one do you hire?
Research the company, find something they need or use in the position you are applying for, and speak both passionately and knowledgeably on it.
Remember in prepping for an interview, you always want to present how well do would be able to perform the actual job they have open. You are always in competition with others, so be the person who shows the most business value to the interviewer.
If the job is one where you will be giving frequent presentations, then concentrate on doing one of that type. For a sales job, do a presentation on a product (don't use a competitor's product for your example), For a design job do a presentation on a design that you are pitching, for a training job, do a training session.