I'd also like to extend a warm welcome to GBaxter7. From the location of Sydney and the use of the phrase "sandwich filings" I assume you are Australian. A quick search on Google Australia shows there are over 900 Subway franchises in Australia now, and I counted 15 in Sydney.
As you can see, all of the other posters so far are American. While the Subway chain of "sandwich bars" started in Connecticut (near New York City), I doubt the sandwich fillings you can select come from the USA. I also note filling differences, such as the fact that you have Swiss, Cheddar and Old English cheese available, while we have American, Monterey Cheddar, Natural Cheddar, Pepperjack, Provolone, and Swiss available.
I don't know how the shops receive meat fillings from the manufacturers in Australia. Here, meats such as turkey, ham, and roast beef are sliced at a factory, then shipped to the shops frozen. There are better meat fillings to be had from other suppliers - which the independent sandwich shops listed in our Sandwiches area tend to use.
I personally don't have any favorite fillings. Most of the taste of the sandwich comes from the "weeds" they put on, such as onions, pickles, jalapeno peppers, and the salad dressing. The only time I now eat there is because I am on the road, and it is the only place handy. Subway franchises are typically taken out by business people, not by people who have a passion to prepare good food.
We had a recent funny thread about the smell inside Subway "sandwich bars": http://www.roadfood.com/Forums/Subway-m540873.aspx
Do your Subways' also smell of baking bread?