The hardest decision I have had to make was whether to TUPE across to another company, where I would have immediately been put on consultation and made redundant a month later, or take a new job in my current employer which would mean relocating from Hampshire to Nottingham. In the end I only had a few hours to make the decision as I only found out at the last minute that the move would be possible.
With the job market at the time I opted for the latter. This meant I could increase my skills in other technologies and has led to more senior positions. It also meant that I could afford to buy my own place and meet some great new people.