It's one of the best, or maybe the best I do not know, action movie of all time. The only sequel that I saw was the number 3, in which Willis partner is Samuel L. Jackson, I heard that the script of that sequel was originally written for Lethal Weapon, however, the original was undoubtedly the best.

Bruce Willis barefoot running over all that glass leaving traces of blood throughout the building while killing the bad guys was great.