Eeyore, Propane is actually odourless in it's pure form. The companies are the ones that add "bitterants" to the propane so that you know if there is a leak or not and to shut off the propane or run away. That's why some propane brands are more smelly than others.
Green gas is propane in pure form with lubricants already added.
If you're shooting indoors it's probably a better idea to use green gas (so your house/basement doesn't smell like propane for months) but outdoors just use propane since the smell will just dissipate.
Now, just a note. People have said the Coleman propane is generally OK and bearable however supposedly one of the least smelly propane brands is the 17 oz "BernzOMatic" ones that Home Depot sells (like the ones that welders use). $3.99+tax at Home Depot (this is the regular "fat" version and not the thin hand held ones like for hand torches and stuff). http://www.homedepot.ca/product/bern...ylinder/977142