you could paint it would be the cheapest way to go. also stucco, slate, its all types of things you could do. but its all in how much your wanting to spend

There are so many things that can be done. The "Cost effective" is the part that is going to cause issues. You can leave it as it is = cheapest option.

I would look at some landscaping to "dress up" the area by the concrete to help conceal the material from view. That way you have done two things: added handsome landscaping (always adds to a home) and hidden the concrete. Tah Dah! Problem solved.

A stacked stone facade used over every STICK of exposed concrete (all the way around...including under the porch) would be my favourite option. I would find a match to the local stone (always the best way to work a home into the landscape it sits on) and have it installed. This is NOT "cost effective"...but it is a nice design option.

Agree on the stone. That's what we did with our last house. Huge improvement.

Home Depot sells a product for painting decks - I think it's called Restore. I painted a concrete porch and steps in a harsh Colorado mountain climate with this product. After 4 winters it still looked great (moved, so don't know how it is now). It comes in several standard colors and they will also custom match any color for you.