America is a land of choices. In India you go to a store, ask the guy there to give you a kilo of chicken, and he hands you a bag of the stuff that you go home and cook it. That doesn't work in America. In the land of the choices, you're faced with breasts, thighs, legs, wings, portions, skinless, boneless, ground, fry, stir-fry, roast, antibiotic, biotic, organic, free range (there's a rumour the average American has to pass an exam before he or she is allowed near the poultry aisle). So which one is the one to choose?
Fear not, I have been there, done that research. Read on, if you're not chicken.
First, if you dont know what cut of chicken is, then here is a guide from the original Spam guys. Online grocer FreshDirect has an excellent section on cuts of chicken complete with pictures but you have to put in a New York zip code (say 10016) to look at it.
The absolute worst pieces to buy for most Indian food is breast. It is commonly recommended for western cooking, but in most Indian curries will turn dry and chewy. The problem is simple - breasts cook very quickly and can't stand up to the long slow cooking of the average Indian curry. No,my favorite part of the chicken is the thigh for the average Indian curry. A mixture of skinless and with-skin thighs on the bone give an excellent package of meat, skin and bone that is just right for most curries. The pieces from a grocer are usually too big though; I cut them up into smaller bite-sized bits. Thighs have a fat bone in the center - if you dont want to cut through the bone (you really need a cleaver for that or you'll get splinters and a damaged knife) then you can cut around it leaving you with four pieces one of which is still attached to the bone. You can even do four boneless pieces and a standalone bone that you discard after cooking.
The other cut that does well is the mixed portion, containing bits of everything. Choose the mixed portions with bone and skin, but throw away most of the skin since chickens here tend to be higher fat than India. American grocers seem to sell larger chunks than Indians usually like, so I cut the portions into bite-sized pieces. Wings (specially half wings and lollipops) cook very nicely in an Indian curry. They're nice juicy bits rich in fat but dont overdo it - many people find it irritating to eat only wings. Legs - they're just too big; they do fine only if you have the patience to chop them up. Drumsticks are often too big too (since the average chicken here is much bigger than its Indian cousin), but the occassionally available smaller drumsticks are very nice. Of course, you can buy whole chicken and cut it up yourself. Buy birds that are two pounds or less and avoid the roaster at all costs (unless actually roasting). Places like Costco sell surprisingly good whole chickens, and they're a whole lot cheaper if making large quantities. If you're worried about cutting them, well whole chickens can be pieced with nothing more than a good chef's knife, as shown here and here. These do it the western way, where the carcass is rejected. In India they don't usually do that but except for special cuts for certain recipes, there is no benefit to retaining the carcass. Just don't remove every bone; bones add volume and taste to the gravy.
There are recipes that call for specific cuts. Tawa Chicken or Kadahi Chicken must absolutely have breast; other cuts don't work because you're cooking quickly on moderate heat. Leg pieces are essential for Tandoori Chicken, Rezala or Chaap. Kalmi or Tangri Kabab needs small drumsticks. Indian food also makes very creative uses of minced chicken - in kababs, in meatballs and as fillings for many things.
There's also the question of which kind of chicken. Free range chicken seems to be the best, and frozen supermarket chicken is definitely the worst - rich, juicy but somehow completely tasteless. The unbranded chicken I find at my local grocer is very good too - that may be the way to go. Cornish hens are tasty, but I find those sharp little bones quite irritating.