He had a great career. He was both a successful tag team wrestler and singles wrestler. Won the WWE Title, WHC, IC Title, US Title and Tag Team Titles. Also won the Rumble, KOTR and MITB, main evented Wrestlemania 24 and was in a world title match at three other Wrestlemanias. He also has been involved in some of the best ladder matches ever.
However, his overall legacy kinda lies somewhere in the middle for me. He is not in the category of guys who drew HUGE money, guys like Hogan and Austin and Rock, who had an industry-changing impact. But he is also not exactly in the category of guys known primarily for being masterful wrestlers in the ring, such as Bret or Flair or Michaels.