should I take a great job (prob what I want to do after a PHD) or do my PHD that I always said I would do? is it worth doing just for the 'fun' of it as this job may not come up again!

I think, you should decide first what are you going to do with your life in future. You can't do a PhD "just for fun". You will have hard, challenging, and not well-paid three or four years of your life. Are you ready for that? If you only dream about reseach and teaching, then your way is a PhD. But if you are interested in real world career, then take the job and enjoy it!!!

Doing a PhD is not "fun". It seems the job is what you want.
Don't waste a lot of time doing a PhD just because at one point you said you wanted to. At Age 7 I wanted to be a Fire Fighter. I didn;t let that declaration spoil my PhD aspirations!!

I agree with George. a phd can only be 'fun' in the sense of fulfilling, if you work hard at it & stay passionate and motivated about your research all the way thro. it is not easy and as George says, not 'fun' in the literal meaning of the word. if you don't see yourself managing that matt, then maybe the job will provide the 'fun' you are looking for, with less effort & less stress.

Couldn't agree more with George!!If you have a good job opportunity grab it!PhD is not "fun". Or it is a step in the plan you made for your future or a mixing of personal realisation and professional ambition like it is for me.