Fish and chips are surprisingly good, especially if you add something like mushy peas as there's a lot less salt and additives than something like pizza or kebab meat.
Or something like chicken kebab with salad and less of the pitta and chips.
But it depends what else you have available. In some places you can only choose from fatty, carby salty food like pizza, kebabs, burgers etc, other places have better choices that involve lots of lean meat, salad, sushi etc, which is obviously better for you, just like you'd do at home - lean meat or fish, pulses, vegetables and salad are better for you than chips, lots of bread or fatty meat and anything processed, so it's the same when choosing a takeaway.
If you're getting Indian, get chicken tikka with no sauce and a curry with pulses and vegetables rather than more fatty sauces with meat and anything deep fried.
Chinese, avoid chips, battered and sweet and sour and go for anything with prawns or chicken and some plain rice.
But whatever you order, don't eat a whole portion. Most takeaways like a large pizza, curry, rice and naan etc are very large and in reality are enough food for two people not one.
So the easiest way to cut it down to a sensible amount of calories is to either save half for lunch the next day or share between more people. If you're honest, you're full before you've finished it, but many people plough on, either because it doesn't occur to them not to, or they see eating until they are stuffed as part of the treat.