Ninja Gaiden BLACK or SIGMA?

[L.C.E.C.]

Ninja Gaiden (I don't intend to buy Just 4 comp) - $10
Ninja Gaiden Black Used (No New Available) - $25
Ninja Gaiden Sigma Used - $27
Ninja Gaiden Sigma New - $30

http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=22097
http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=39622
http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=65650
http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=8778

What I've learned / Deciding factors:

- So NG:B has a harder difficulty level, and Sigma was eased up a bit in general?

- Ninja Gaiden Black has the NES original, but that's not really deciding factor,
becuase if I wanted that game, I could get it for virtually nothing

- Ninja Gaiden Sigma has better graphics

- NGS is in HD

- The XBOX controller is slightly better for NG

- NGS has some extra, but crappier, slower missions as Rachel that don't affect
the story at all

- NGS has a new move w/ sixaxis that's not in NG:B?

- NGS has a better, but still flawed camera

- I have more games on my 360 than my PS3

ANYTHING I'M MISSING?