The most important attribute you can exhibit during a job interview is “heart.” It sounds corny, but the emotional vibe you throw off, the look in your eyes, the depth of your care and interest are palpable to an interviewer. You radiate your interior. Look in the mirror and take a deep breath before you walk in. The attitude you project during the first thirty seconds will help the interviewer believe you’re like that every day. Don’t be a nut, but be up and interested, not skeptical and distant.
If you think you really want the job, say so at the end of the interview. “I want this job more than anything.” People rarely go for it like that. But that’s the kind of passion that will probably get it for you.