WEAPON OF CHOICE Last week's U.S. attack against terrorists marks the fifth time military planners have reached for the Tomahawk since the missiles first saw combat in the 1991 Persian Gulf war. Before cruise missiles, it took pilots in warplanes to do the job. The increasing reliance upon Tomahawks has caused some worry among fliers' ranks and celebration among cruise missile proponents. A rivalry of sorts has developed in the Navy. On one side are the naval aviators. On the other side are those who man and sail Navy surface combatants armed with Tomahawks. Evidence of this comes from the following humor seen circulating among Pentagon offices in recent years. It is entitled "Top Ten Reasons Why Tomahawks Are Better Than Attack Pilots" 10. Tomahawks make lousy Prisoners of War. 9. Tomahawks don't sleep 'til they are hungry and eat 'til they are tired. 8. You don't need to outfit a Tomahawk with a Rolex and leather flight jacket to do the job. 7. Tomahawks don't complain. 6. Tomahawks don't need eight hours of sleep before a mission. 5. Tomahawks don't require costly flight pay bonuses. 4. Tomahawks don't make excuses when they miss the target. 3. Tomahawks won't bore you to death with stories when the mission's over. 2. Tomahawks always follow the flight plan and never hot-dog it. And the No. 1 reason why cruise missiles are better than attack pilots: 1. You'd let your sister date a Tomahawk.