Nearly any airline will give you mid level (Gold) status. I know for a fact DL and CO will. AA is the only one that can be tricky, they like to push people to challenges, but I once got a comp to Plat (AA mid level status), by being persistent. Also airlines like BA I don't think they hand out comps like candy either. There is also a widely posted concept that these comps are "once in a lifetime" but I would take that too with a grain of salt. I personally have gotten more than one comp in one program in "this life"
.