Nothing is better than having a fresh smelling house. From pets, to garbage, to cooking, scents can accumulate to make a very stinky impression. One of my favorite new finds has been the Slatkin & Co. Candles from Bath and Body Works. I haven't found any candles in this price range that can fill an entire house with such amazing aromas. Regularly priced they cost $19.99, but if you wait for the regular sales events, you can get much better deals- usually around $9.99 for a 14.5 oz candle. For an even better deal, check their clearance marked items.
I like to light mine about an hour to thirty minutes in advanced before guests arrive, just enough time to fill our entire two story house with a clean, welcoming scent. I almost always have a positive comment from guests regarding the inviting smell when they first walk in the house, and to me, that's totally worth it!