There are several fish that could be considered substitutes for red snapper, but none compare to the flavour and texture it offers. Grouper is known as one this type of substitute because they have white meat like most types of snapper do. Halibut can also offer similar qualities in taste even though its flesh may not look identical to  a Red Snappers'. Trout might work well with some people too since many trout recipes use strong seasonings which make up for what's missing from their natural flavours.