Now that is interesting. I read the thread title, I'm sitting here at work and I smell popcorn, and was about to reply this very thing before I even read the thread. Sure enough, that was the first thing listed!
Everything apart from fish, fish infact makes me want to leave the house cooking fish makes the house smell like someone has died and hasn't been discovered yet.
Like the above I would have to agree with the Fry Up - bacon always makes me feel hungry. Also the smell of a BBQ - yum yum!