Instead of grass, what can we put on our backyard lawn?

Clover

clover I hear.

I guess it really depends on the size of your yard. I like pea gravel as it is easy to walk on and you can add pavers of your choice to an area along with the pea gravel to create a great outdoor seating area. Be sure to remove any grass, etc. and put down landscaping barrier prior to adding the pea gravel for easy maintenance.

Mulch bought by the cubic yard is fairly inexpensive, you could do pathways using a combination of mulch and pavers...

rock garden

Gravel or mulch

I think the question would be , will you be entertaining?, or just can't keep up the yard, for as cutting the grass?. If the yard is already just dirt no grass, I agree with Beth and to use Pea Gravel for a large area.