Deep blue fish&chips. Also on Cherry Hinton Road. Have tried, and was pretty good from what I remember.

Having said that, if you are in Cambridge and not eating Gardies kebabs, you may well be making a grave error.

EDIT: Some googling seems to suggest that Jacks and Deep Blue may in fact be the same place, oddly by different names.
(Serotonicity was a naughty boy on..., Mon 30 May 2011, 13:01, 2 replies)

Gardies kebabs?
I must admit, I'm not a kebab lover but if they are *that good* I may give them a go. Where might they be found? (because I am too lazy for google... :P)
(Petite chien is going to do science to it, Mon 30 May 2011, 13:37, closed)

I was always a fan of...
...Istanbul (East Road) and Bosphorus (Mill Road).
(SonoraAeroClub "OH SWEET HELEN OF BALLS!", Mon 30 May 2011, 16:15, closed)

seconding Gardies
Just off Trinity Street, down from McDonalds.
(four, Mon 30 May 2011, 17:41, closed)

I am going to have to try all of these
Goodbye, this month's stipend...
(Petite chien is going to do science to it, Mon 30 May 2011, 17:55, closed)

This
I was just going to recommend Deep Blue but have been beaten to it - twice, it would seem.

Have a third recommendation though.
(sanity challenged, Mon 30 May 2011, 16:54, closed)