Ostrovitsky's bakery or Isaac's bake shop - both on Avenue J - have really good egg challot (Ostrovitsky's makes a delicious whole wheat - probably the best I've tried - if you're interested). For water challot I would go with Eagle's, on thirteenth avenue in Boro Park
Williamsburg is a haven for the finest heimash water challa
I agree with EvanM about Tiferes (on Lee Ave next to Felty Hats- dont remember cross st.)
Their challa are great for Friday night but loose it bt Shabbos lunch- Cool place to shop.
Pick up a paper shopping bag & select a challa from 4 sizes - all are baked mostlly in a oval form & have a mushroom top - they also have chocolate & vanilla ruggalach -comes in round & oval shapes- Erev Shabbos hot challas & ruggalach are always popping out of the oven-
Also on Lee Ave. off Rutledge is Oneg- their challa is a little heavier ( I like those better ) They hold up better Shabbos Lunch .. They have a bigger selection of other baked goods & have the same type of ruggalach
I think the ruggalach are a Satmar thing- I have seen all the bake shops have them-
Cant remember all the names but drive on Bedford around Lee & then to Marcy -There are a dozen bakeries - Shopping Williamsburg is a real experience - Give yourself a little time - parking is a hassel Erev Shabbos & YomTov