What brand of scented candle works the best?

It's not the candle, but a good wick in the candle. Stay with the soft smells (which you can obviously smell.) Vanilla can be a sickening smell while peony or other softer scents and lime/lemon can have a refreshing smell. Scented candles should never be used around food or while eating at a dining room table. I have found that so many of my friends have allergies I get the non scented candles instead. I simply open my doors to let in some fresh air. Earlier on before guests come you can Fabreeze your couches, rugs, etc. (with a door open) to freshen things up.