Commentary

Booch et. al.'s book is the most authoritative and follows the 1.3 standard. It is conceptually quite hard at places. Some examples are rather sketchy, and language bindings (Java or C++) are touched upon only briefly. Quite expensive ($\sim$ 40 U. K. Pounds).

Eriksson et. al.'s book is about UML 1.1. It is well written, and comes with a demonstration version of Rational Rose (version 4) and has a complete case study example (though somewhat simple). This version of Rational Rose differs appreciably from the current commercial version, though. Cheaper ($\sim$ 35 U.K. Pounds)

Fowler et.al.'s book also uses UML 1.1. It is a rather slim volume with good examples. The technical content is excellent, though quite hard. Cheapest of the three ($\sim$ 25 U.K. Pounds).