It is pretty difficult to actually find concrete information about which products have the most and least environmental gain from recycling.
The two clear winners for household recycling are:
Aluminum cans
Cardboard
Glass recycling can be either environmentally positive or negative, depending on the application. If glass is made into new glass bottles, that is a positive environmental transaction. But, a lot of recycled glass is of low quality and can only be crushed to use as road fill and other similar applications, which is a net environmental negative.
And I gather that #1 and #2 plastics are much less energy-intensive to recycle than #5.
So... all that is to say, reducing and reusing are much better environmental choices than recycling. Thankfully, as the recycling technology improves, the environmental benefit increases.
