My old job was almost perfect. I was a systems engineer for a research network. My duties were to configure, build, install, secure, manage and repair Linux hosts used for research on projects so advanced/cutting edge that I could spend days just listening to researchers explaining them and I honestly loved it! I understood less than half of the projects but just seeing how motivated and excited the researchers are made the job my favourite. Unfortunately I had to leave and get a job closer to my house because having a 2 hour (one way) commute for two years was killing me :-/ relocation wasn't an option and still isn't but I'd be lying to myself if I tried to say I wouldn't go back as soon as I could.