I'll always have a Glasshouse candle in the house. My favorites so far have been the (now discontinued) Sassafras, Esperance, and Rio de Janeiro (currently burning). Next on the list is Marseille - you can't beat a good gardenia fragrance.
Diptyque are more expensive, but for fragrance quality they really can't be beaten. Again I love their Gardenia candle, and their Roses candle is the most realistic version I've found. The Jonquille candle is hated by my boyfriend (I think its a male thing as my father & Grandfather aren't keen either) but this flower will always remind me of my Grandma.
I have never tried the Tocca candles, but I intend too. They have the most beautiful florals. Florence is first on my list.
I must include Jo Malone (also from David Jones) as well for the incredible variety of fragrances they have. There really is something for everyone. What I like best though is that they are fairly unadulterated (you may have noticed most of these recommendations are) with only one or two scents.
These may not be the cheapest candles on the market, but they are a simple, elegant luxury that I find irresistible. An instant pick-me-up for my over-stuffed, bending under the weight, IKEA bookshelves.