My husband and I will be in NYC for a week in early May and would like your recommendations for Greek and Indian restaurants. We do not do the "fancy" white tabel cloth restaurants, but instead prefer the more local restaurants that are more casual. We are staying near Rockefeller Center, but don't mind a walk or taxi ride to get there. Looking forward to hearing from you!!

for some authentic south indian food take a cab ride to lexington from 26th to 28th.
my personal favourite is pongal.
but there are others around that neighbourhood that are also pretty good.
most of the restaurants there tend to be south indian but there are some indian/pakistani curry houses also.
none of these are remotely fancy like devi, tabla, tamarind or dawaat.
the prices here are a fraction of the fancy ones and the food is authentic and not fusion indian which is what the fancy ones tend to do.

For the best Greek food you can hop in a cab or take the 7 train to Astoria Queens....any restaurant there is fabulous!

For casual greek food check out Kefi on the UWS, for an outstanding but expensive meal, Milos in midtown. In the east village there is Pylos

for casual fusion indian, i like the Bread Bar at Tabla, they have a great patio overlooking Madison Square park, it's not fancy like Table proper and the Tamarind Margarita is delish.

Indian - Tiffin Walla (vegetarian) on the corner of 28th & Lexington Ave is excellent, home style food. The beauty of this place is that you get a good variety of south Indian as well as stuff from other parts of India... all of which is done really well. I love the cauliflower there as well as the dosas. My favorite place in the Curry Hill neighborhood.
Saravanaas on the NorthEast corner of Lexington and 26th is probably the best exclusively South Indian restaurant in NYC.
A meal for 2 at both these places shouldn't cost more than $40-$45 total.

Contrary to popular belief, Tamarind isn't fusion Indian (Tabla etc are indeed fusion.). It is an excellent but upscale Indian restaurant that has the best lamb chops I've had. If you like kebabs & grilled meats, a cheaper alternative is Banjara.
Sangam in Greenwich Village is a complete hole in the wall with seating fro 6-8 people and specializes in Biryani - one of the best around at a very reasonable $10. The mince meat rolls are very good too. If you're in the hood try the rolls, even if it's a snack in the afternoon.

Greek - another fav cuisine of mine.
Places in Astoria have a reputation that's great but I've not been blown away... maybe you really have to know where to go & what to order as I've found most places inconsistent.
If you want excellent Greek, maybe as good as some of the best in Greece itself, Milos and Molyvos have been consistently among the best. Milos is extraordinarily expensive, Molyvos less so, but up there.
Snack Taverna in the West Village is my favorite mid-price Greek. Weekday lunch is a steal at around $9-$13 an entree. Don't miss this place. Pylos in the East village is also good but I prefer Snack Taverna.
If you want to try whole grilled fish at these Greek places, you should try Mary's Fish Camp or Pearl Oyster Bar in the West Village. New England shack style restaurants that serve an eclectic variety of whole grilled fish daily.

Another vote for Pylos. Keffi on the UWS is popular and very reasonable. It recently moved to Amsterdam betw 84 and 85th.

mdn - Snack Taverna sounds nice - I will try it.

Another vote for Pylos, Saravanaas, and Banjara.
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I'd recommend Agnanti in Astoria, but its location on Ditmars Boulevard across from Astoria Park is not accessible by subway.

thank you all so much for the recommendations - I have put then in my trip folder and am sure we will hit at least 2-3 of these during our visit!