I love to melt tarts in my house - I find that they smell better and fill up the house with scent much more quickly than ordinary candles.
I'm always searching for strong tarts that don't cost a fortune (Yankee candles are great but $2-3 per tart is too much for me). My local Hobby Lobby is now carrying a product called ScentSationals. There is an electric warming unit that melts the tart. The tart refills come in packs of 6 for $3.99. Most important, the smell is FANTASTIC! Super strong and they melt within 20 minutes. I've tried Cranberry Spice and Crackling Birch.
I'm amazed at how such a small tart can put out such a strong scent. I will definitely be trying the other scents.