
Everything on the top row is most definitely a sandwich, and anyone who says otherwise is an idiot. A sub is also clearly a sandwich. The hot dog and ice cream tacos are more curious examples, and I think there's a distinction that hasn't been made here. You see,
sandwiches are usually stacked vertically. Hot dogs and tacos, on the other hand, are stacked "horizontally," which makes them harder to call sandwiches. Personally, I find hot dogs to be on-the-fence, while I wouldn't classify tacos (regardless of the contents) to be sandwiches. The difference between the two is that the bread on hot dogs are much thinner where the two "parts" of the bread connect, and so there's a bifurcation. On the other hand, tacos don't have this, and thus the "bread" is not clearly divided into two; this makes it not a sandwich. Sensible people can disagree here, though. Nothing on the bottom row is a sandwich. Open-faced "sandwiches" are lies, and are not sandwiches.
IN SUMMARY:Traditional Sandwiches: Yes, obviouslySubmarine Sandwiches: YesHot Dogs (or similar): MaybeTacos (or similar): No, but I can see opposing argumentsWraps, bruchetta, Pop-Tarts, etc: No, obviously