Take out in Chelsea/West Village
Agree with Chuck that Grand Sichuan is probably the best option for authentic Chinese in the area. Sichuan Gourmet is another decent option.
For north Indian, Indian Taj in the Village isn't bad. If you want something fast, Kati Roll is an inexpensive option for the basic, eponymous sandwich. For south Indian / Sri Lankan, Thiru's dosa cart on Washington Square South is an option during the day (I think until 5 p.m.?) for dosa, iddly and on Tuesdays, vada, if he still follows the same vada schedule he did a few years ago. It's not the best food, but there's really no other competition that I know of in the area for south Indian other than the not-very-good dosa at Cafe Spice.
Options are also fairly limited for Cuban, I think. There's Cuba (many people like it; I've only been there once and don't remember much other than the very, very high noise level), Favela Cubana and Havana Alma de Cuba (haven't tried them), and Little Havana (fair for very basic dishes).