I got a £50 Marksman 2 stroke, at 400w it is plenty big enough to run a fridge and a set of gazebow lights, and not too noisy. A full tank of fuel lasts about 6 hours on full load.This year at Le Mans we got a large polystyrene box and put it over the genny to muffle it and it was virtually silent.
I also got a Hilti 4 stroke, it is 3kw so has plenty of power but it is very noisy and drinks unleaded like your average Houx Annexe punter drinks lager. Another problem is, it is the size of a small fridge and weighs about 60 kg, something else to consider when loading cars or vans.
Next year we are gonna get a couple more cheap 2 strokes rather than take the 4 stroke.