I think M&S and Charlie Bigham are both good, and they're amongst the many brands available from Ocaco. The ready meals are divided into types such as Indian, Italian etc. and the "meal deals" are there. Cook are really good too.
We also use microwave rice which can be plain or flavoured, all the brands seem OK, they cook in 2 minutes and you keep them in the cupboard rather than the fridge. I try to avoid buying meals with the rice in the same pack if possible as the whole meal is quite small and short on protein. Apparently frozen rice and mashed potato are good, though I've never tried them.
We also like haggis for a change, they can also be bought in slices but I don't think that they can be cooked from frozen.
Many simple meals can also be cooked quickly in the air fryer: fishcakes, chops, scampi and fish (portioned or whole).