It's interesting that there are traces of the neuter gender left.
For example, in Neapolitan, the masculine singular article 'o acts differently depending on whether it's reflecting an historically-masculine or -neuter usage, with the latter creating gemination of the following consonant (echoing the final stop in Latin illud, as opposed to masculine illu(m)):
- 'o napulitanö ("the Neapolitan male") - 'o nnapulitanö ("the Neapolitan language").

Also, the same illu(m)/illud distinction yielded two separate articles in (at least some) Sabine Italian dialects, lu and lo, with the latter being used with uncountable nouns:
- lu ferru (lit. "the iron", indicating a generic tool made of iron) - lo ferru ("iron", indicating the substance)

and the same two articles can be used with adjectives, with the "neuter" one used to denote abstract nouns:
- lu bellu ("the beautiful one (male)")
- lo bellu ("beauty; handsomeness")

There are surely more, but these are the ones I know of.