I tend to buy the ones that don't come with their own accompaniment for example the curries that just come on their own (not with rice) this is because ready meal rice tastes vile, and often comes with peas and or sweetcorn - yuk! Also, I find that ready meal tend to be cooked with ingredients I don't like as I'm very fussy. For example, I don't really like anything that's cooked with wine or beer or brandy
I don't generally get ready meals of something I could cook myself, but would get things that are harder for me to cook like Battered prawns or sesame prawn toast. the main exception is lasagne because, let's face it, it's an utter faff to cook from scratch