For those who are sensitive to sulphites, low-sulphur wines can open up your options. Sulphites feature in most wines; whites more than reds, and sweet wines significantly more than both. They prevent oxidation (that is, they stop the juice turning brown), they keep wines stable (important when they have to travel) and they preserve their bright, fresh fruit flavours. The downside is that higher levels can, in some people, provoke headaches and breathing difficulties, though headache can of course also be triggered by the amount you drink.
The bad news for those who are looking for NAS wines is that they are not that widely available, they’re generally quite expensive and, if you’re used to the bright fruit flavours of conventionally made wines, you may even not like them (that said, like low-sulphur wines, they generally benefit from decanting).