Lone Star is a very inexpensive, low-quality beer along the lines of the now defunct generic beer available in previous decades.
Its claim to fame is that is available exclusively in Texas, much like its slightly higher-quality cousins such as Ziegenbock.
Lone Star compares favorably in terms of quality and price with other local cheap beers, such as Olympia, found in the Pacific Northwest.
As one would expect, Lone Star tastes much like any cheap, relatively light beer; the closest comparison I can think of is probably either Budweiser or MGD. It has two advantages over those beers, however: 1) it is much cheaper and 2) it is made in the Republic of Texas.