I think it really depends on where you are trying to go and your personal style.
Low End: Target has great suits. I wore one to a Kellogg event and everyone kept telling me how great my suit was, and I normally wear designer (Bloomingdales) but I didnt have a black, navy or grey suit for this weekend event. I wore a grey suit (dk grey) blue dress shirt, pearl earrings and necklace, and navy pumps.
Mid Price (But Designer): Marshalls, TJ Max- yeah you will have to search but you can find some really nice suits there for 1/2 price. I think Banana R. suits are non-traditional and can be too fashion forward and the fit is not perfect.
Fashion High End: Ralph Lauren, Elie Tahari, Theory
Elie Tahari is my favorite next Ralph Lauren. The suits fit right, not too big or small, they have a more modern look and young attitude. My Theory pants are great, as they do not wrinkle, stain resistant, and always look good, year after year.