I bet you can guess.... it's the religious candle! (or known fondly as the 'Jesus Candle')
The best thing about religious candles is their price -- $1.00! -- dirt cheap at the Dollar Store or at your local grocery store/Bodega.
The dollar price means you can buy lots and lots with out breaking the bank, and I think they look great en masse. I used them in bulk around the pool at the past summer's Hudson Wood's launch party (below), and just a few in my own apartment (above).
The also last fooorreeevvverrr so they're ideal for events and parties when you can't be worrying about the candles burning out and the glass container keeps the wax from dripping and spilling.
See? They're just the best!
I prefer the all white versions, but for a quirkier look, they come in a variety of color with religious images.
Other uses could be lining stair steps as seen via Cottage and Vine...
You can also decorate the outside glass with gold leaf as seen here...