The proudest bug I've ever fixed came from working with the team using our software. They had a task that should take 5 minutes that the have to do several times a day but it was taking 30 minutes, 25 of those minutes was spent finding the right item in a massive list in a combo box (think medical codes). The only fix required was to an an order by clause so they could find what they were looking for, but they couldn't get approval for it. I took up the cause for them but couldn't get approval either, I couldn't get this two second task to be deemed a business priority and had to sneak the change in, risking my own ass.
The woman who had been wasting this time for years came up and hugged me in tears. No one was getting fired but I'd just freed up enough time that she didn't have to work overtime everyday. It was such a simple change and lifted such a weight off the users shoulders that went undone for years because nobody actually watched them using our software.
Unfortunately someones authority was undermined and I was let go a few weeks later.