I love sushi train style dining. My favourites are Sushi Railway at Stones Corner in Brisbane and Sushi Ave. in Surfers Paradise.
Sushi is the ultimate 'fast food' with options for vegetarians, gluten free and children (or fussy eaters!). Because you see it being made you know it's fresh and can request your favourites.
Oddly, some people think sushi is raw fish - and fresh raw fish is an option (the salmon is great) but the variety available is huge - avocado and chicken, egg, cucumber ... all delicious! Most sushi places also offer a range of hot options.