I'd avoid daewoo like the plague.
I had one from the coop website for I think it was about £90 quid.
Daewoo KOC9Q3T 28L
it started to make a grinding sound from the turntable motor after a few weeks.
got it swapped out again same thing happened..
asked if I could just choose a more expensive model and pay the difference so went with a Panasonic one instead which has been faultless and the auto sense cooking options are calibrated perfectly

Panasonic NN-CT870WBPQ 32L Deluxe
definitely try to get one with an inverter if you can find one within your budget
Newer models have inverter power supplies which use pulse width modulation to provide effectively continuous heating at reduced power so that foods are heated more evenly at a given power level and can be heated more quickly without being damaged by uneven heating.
Non inverter models can't modulate so just go from on full power > off > full power with the off time depending on what setting you choose so like on the lowest setting it would bombard your food on full power , big pause , bombard your food on full power rinse and repeat
My colleague tells me to get a convection one, more useful.
yea mine goes from 40c-250c

awesome for cooking pizza
can use microwave + grill + oven mode at the same time for speedy cooking as well, jacket potatoes come out in about 20 minutes looking and tasting exactly the same as they would if they have been in an oven on 180 for an hour+
coop are really good 60min time slot + free delivery
http://www.coopelectricalshop.co.uk/Small+Appliances/Microwaves/fd/c/c
tend to be cheaper or the same price as places that charge for shipping and as seen in this post the customer support is awesome.
they literally had a courier at my house the next working day both times to swap out my microwave