Morrowind delivers on what it says on the box "Explore another world". It"s amazingly rich and detailed. You can follow any number of quest lines or just go out and do whatever you feel like (and deal with the consequences).
System requirements are a bit steep however. I have a P4 1.6 512 MB DDR and a GeForce4 mx and am only able to run it comfotrably at about 35% of the maxed out settings. Still it"s beautiful and completely captivating. Morrowind is a bit like GTA3+D&D with an exponentialy larger world.
If you are capable of sustaining any sort of higher brain functions, buy this game... you won"t be sorry.