My wife and I just remodeled our open living room / kitchen. We have a slab foundation and decided to go with ... the slab foundation.
Seriously. 500 square feet of finished floor just cost us $300 installed, for a finished cost of $0.60 / sq. ft. I removed two layers of terrible tile in the kitchen and carpet in the living room. I used a 7 inch grinder with a diamond cup wheel to remove thin-set and glue and prepare the surface, and then laid down a coating of epoxy. We used a product called Rocksolid Metallic, and now we have floors that are all one level, very pretty, multi-tone and shiny. It cost significantly less than any other flooring solution we could think of, even including the cheapest wholesale laminate available. The epoxy was on clearance at Lowes for 50% off (actually marketed as garage flooring in the US, but was originally designed for interior). If it wasn't, then we would have probably just gone with a solid color epoxy for about the clearance price of the fancier stuff.
We got the idea when we lived in Prague for half of the year last year. Every home we went in to including the one we were living in was painted or epoxied concrete floors. It does have the disadvantage of being "cold," but no colder than the tile-on-slab we have elsewhere in the house.
Until Prague, I never even considered just grinding down the already sturdy, durable, and easy to clean flooring system that typically lives under all that expensive, harder to maintain flooring.