MAC's Club eyeshadow is a very popular colour that a lot of other companies make 'dupes' of. A dupe a name the makeup community has given to anything which closely resembles or copies a particular product, usually something more expensive, hard to find or discontinued.
Club itself is a pressed, satin finish shadow, which MAC describes as a "red-brown with green pearl". In this post I've rounded up all the colours I have which are similar to this in my eyes. The eyeshadows that I am comparing are: MAC Club, MUA Shade 12, MAC Blue Brown Pigment and a shade from Famous by Sue Moxley which I got in the 'complete face kit'. I believe that the Sue Moxley colour is also available as a single eyeshadow, however I don't have it so can't compare or give you a shade name, sorry!
However, you put it over a coloured base and the green shows itself! I'm not sure if it's obvious from the picture, but Club leans more green than any of the others when you put it over the green base. Here I used the NYX Jumbo Eye Pencil in Rocky Mountain Green.
I think overall, any of these are great in place of Club if you want that type of colour, but none are identical. A massive plus for the MUA eyeshadows has to be the price, as they are £1 each, so if price is a concern you can't go wrong with that one if you can get your hands on it!
Hope this was useful :)